Remove NSObjectRetain/Release

These shouldn't exist; smart pointers should be used. Given that
they're only used in one place, remove them with some refactoring.

Do some additional C++ modernization to gfx::Image while we're there.

Bug: none
Change-Id: I603a4c5ab3693c2ee7dfd4b5059f99cbc1baea15
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3434388
Reviewed-by: Mark Mentovai <mark@chromium.org>
Reviewed-by: Robert Sesek <rsesek@chromium.org>
Commit-Queue: Avi Drissman <avi@chromium.org>
Cr-Commit-Position: refs/heads/main@{#966996}

base/mac/foundation_util.h

@@ -138,10 +138,6 @@ TYPE_NAME_FOR_CF_TYPE_DECL(SecPolicy);
 
 #undef TYPE_NAME_FOR_CF_TYPE_DECL
 
-// Retain/release calls for memory management in C++.
-BASE_EXPORT void NSObjectRetain(void* obj);
-BASE_EXPORT void NSObjectRelease(void* obj);
-
 // Returns the base bundle ID, which can be set by SetBaseBundleID but
 // defaults to a reasonable string. This never returns NULL. BaseBundleID
 // returns a pointer to static storage that must not be freed.

base/mac/foundation_util.mm

@@ -231,16 +231,6 @@ TYPE_NAME_FOR_CF_TYPE_DEFN(SecPolicy)
 
 #undef TYPE_NAME_FOR_CF_TYPE_DEFN
 
-void NSObjectRetain(void* obj) {
-  id<NSObject> nsobj = static_cast<id<NSObject> >(obj);
-  [nsobj retain];
-}
-
-void NSObjectRelease(void* obj) {
-  id<NSObject> nsobj = static_cast<id<NSObject> >(obj);
-  [nsobj release];
-}
-
 static const char* base_bundle_id;
 
 const char* BaseBundleID() {

base/mac/mac_util_unittest.mm

@@ -93,18 +93,6 @@ TEST_F(MacUtilTest, TestGetAppBundlePath) {
   }
 }
 
-TEST_F(MacUtilTest, NSObjectRetainRelease) {
-  base::scoped_nsobject<NSArray> array(
-      [[NSArray alloc] initWithObjects:@"foo", nil]);
-  EXPECT_EQ(1U, [array retainCount]);
-
-  NSObjectRetain(array);
-  EXPECT_EQ(2U, [array retainCount]);
-
-  NSObjectRelease(array);
-  EXPECT_EQ(1U, [array retainCount]);
-}
-
 TEST_F(MacUtilTest, IsOSEllipsis) {
   int32_t major, minor, bugfix;
   base::SysInfo::OperatingSystemVersionNumbers(&major, &minor, &bugfix);

ui/gfx/BUILD.gn

@@ -95,6 +95,7 @@ component("gfx") {
     "image/image.h",
     "image/image_family.cc",
     "image/image_family.h",
+    "image/image_internal.h",
     "image/image_platform.h",
     "image/image_png_rep.cc",
     "image/image_png_rep.h",

ui/gfx/image/image.cc

@@ -15,6 +15,7 @@
 #include "build/build_config.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "ui/gfx/geometry/size.h"
+#include "ui/gfx/image/image_internal.h"
 #include "ui/gfx/image/image_platform.h"
 #include "ui/gfx/image/image_png_rep.h"
 #include "ui/gfx/image/image_skia.h"
@@ -30,82 +31,31 @@
 
 namespace gfx {
 
-namespace {
-
-using RepresentationMap =
-    std::map<Image::RepresentationType, std::unique_ptr<internal::ImageRep>>;
-
-}  // namespace
-
 namespace internal {
 
-class ImageRepPNG;
-class ImageRepSkia;
-class ImageRepCocoa;
-class ImageRepCocoaTouch;
+ImageRep::ImageRep(Image::RepresentationType rep) : type_(rep) {}
 
-// An ImageRep is the object that holds the backing memory for an Image. Each
-// RepresentationType has an ImageRep subclass that is responsible for freeing
-// the memory that the ImageRep holds. When an ImageRep is created, it expects
-// to take ownership of the image, without having to retain it or increase its
-// reference count.
-class ImageRep {
- public:
-  explicit ImageRep(Image::RepresentationType rep) : type_(rep) {}
+ImageRep::~ImageRep() = default;
 
-  // Deletes the associated pixels of an ImageRep.
-  virtual ~ImageRep() {}
+const ImageRepPNG* ImageRep::AsImageRepPNG() const {
+  CHECK_EQ(type_, Image::kImageRepPNG);
+  return reinterpret_cast<const ImageRepPNG*>(this);
+}
+ImageRepPNG* ImageRep::AsImageRepPNG() {
+  return const_cast<ImageRepPNG*>(
+      static_cast<const ImageRep*>(this)->AsImageRepPNG());
+}
 
-  // Cast helpers ("fake RTTI").
-  const ImageRepPNG* AsImageRepPNG() const {
-    CHECK_EQ(type_, Image::kImageRepPNG);
-    return reinterpret_cast<const ImageRepPNG*>(this);
-  }
-  ImageRepPNG* AsImageRepPNG() {
-    return const_cast<ImageRepPNG*>(
-        static_cast<const ImageRep*>(this)->AsImageRepPNG());
-  }
+const ImageRepSkia* ImageRep::AsImageRepSkia() const {
+  CHECK_EQ(type_, Image::kImageRepSkia);
+  return reinterpret_cast<const ImageRepSkia*>(this);
+}
+ImageRepSkia* ImageRep::AsImageRepSkia() {
+  return const_cast<ImageRepSkia*>(
+      static_cast<const ImageRep*>(this)->AsImageRepSkia());
+}
 
-  const ImageRepSkia* AsImageRepSkia() const {
-    CHECK_EQ(type_, Image::kImageRepSkia);
-    return reinterpret_cast<const ImageRepSkia*>(this);
-  }
-  ImageRepSkia* AsImageRepSkia() {
-    return const_cast<ImageRepSkia*>(
-        static_cast<const ImageRep*>(this)->AsImageRepSkia());
-  }
-
-#if BUILDFLAG(IS_IOS)
-  const ImageRepCocoaTouch* AsImageRepCocoaTouch() const {
-    CHECK_EQ(type_, Image::kImageRepCocoaTouch);
-    return reinterpret_cast<const ImageRepCocoaTouch*>(this);
-  }
-  ImageRepCocoaTouch* AsImageRepCocoaTouch() {
-    return const_cast<ImageRepCocoaTouch*>(
-        static_cast<const ImageRep*>(this)->AsImageRepCocoaTouch());
-  }
-#elif BUILDFLAG(IS_MAC)
-  const ImageRepCocoa* AsImageRepCocoa() const {
-    CHECK_EQ(type_, Image::kImageRepCocoa);
-    return reinterpret_cast<const ImageRepCocoa*>(this);
-  }
-  ImageRepCocoa* AsImageRepCocoa() {
-    return const_cast<ImageRepCocoa*>(
-        static_cast<const ImageRep*>(this)->AsImageRepCocoa());
-  }
-#endif
-
-  Image::RepresentationType type() const { return type_; }
-
-  virtual int Width() const = 0;
-  virtual int Height() const = 0;
-  virtual gfx::Size Size() const = 0;
-
- private:
-  Image::RepresentationType type_;
-};
-
-class ImageRepPNG : public ImageRep {
+class ImageRepPNG final : public ImageRep {
  public:
   ImageRepPNG() : ImageRep(Image::kImageRepPNG) {
   }
@@ -116,7 +66,7 @@ class ImageRepPNG : public ImageRep {
   ImageRepPNG(const ImageRepPNG&) = delete;
   ImageRepPNG& operator=(const ImageRepPNG&) = delete;
 
-  ~ImageRepPNG() override {}
+  ~ImageRepPNG() override = default;
 
   int Width() const override { return Size().width(); }
 
@@ -125,9 +75,9 @@ class ImageRepPNG : public ImageRep {
   gfx::Size Size() const override {
     // Read the PNG data to get the image size, caching it.
     if (!size_cache_) {
-      for (auto it = image_reps().begin(); it != image_reps().end(); ++it) {
-        if (it->scale == 1.0f) {
-          size_cache_ = it->Size();
+      for (const auto& it : image_reps()) {
+        if (it.scale == 1.0f) {
+          size_cache_ = it.Size();
           return *size_cache_;
         }
       }
@@ -146,7 +96,7 @@ class ImageRepPNG : public ImageRep {
   mutable absl::optional<gfx::Size> size_cache_;
 };
 
-class ImageRepSkia : public ImageRep {
+class ImageRepSkia final : public ImageRep {
  public:
   explicit ImageRepSkia(ImageSkia image)
       : ImageRep(Image::kImageRepSkia), image_(image) {}
@@ -154,7 +104,7 @@ class ImageRepSkia : public ImageRep {
   ImageRepSkia(const ImageRepSkia&) = delete;
   ImageRepSkia& operator=(const ImageRepSkia&) = delete;
 
-  ~ImageRepSkia() override {}
+  ~ImageRepSkia() override = default;
 
   int Width() const override { return image_.width(); }
 
@@ -169,171 +119,67 @@ class ImageRepSkia : public ImageRep {
   ImageSkia image_;
 };
 
-#if BUILDFLAG(IS_IOS)
-class ImageRepCocoaTouch : public ImageRep {
- public:
-  explicit ImageRepCocoaTouch(UIImage* image)
-      : ImageRep(Image::kImageRepCocoaTouch),
-        image_(image) {
-    CHECK(image_);
-    base::mac::NSObjectRetain(image_);
-  }
-
-  ImageRepCocoaTouch(const ImageRepCocoaTouch&) = delete;
-  ImageRepCocoaTouch& operator=(const ImageRepCocoaTouch&) = delete;
-
-  ~ImageRepCocoaTouch() override {
-    base::mac::NSObjectRelease(image_);
-    image_ = nil;
-  }
-
-  int Width() const override { return Size().width(); }
-
-  int Height() const override { return Size().height(); }
-
-  gfx::Size Size() const override { return internal::UIImageSize(image_); }
-
-  UIImage* image() const { return image_; }
-
- private:
-  UIImage* image_;
-};
-#elif BUILDFLAG(IS_MAC)
-class ImageRepCocoa : public ImageRep {
- public:
-  explicit ImageRepCocoa(NSImage* image)
-      : ImageRep(Image::kImageRepCocoa),
-        image_(image) {
-    CHECK(image_);
-    base::mac::NSObjectRetain(image_);
-  }
-
-  ImageRepCocoa(const ImageRepCocoa&) = delete;
-  ImageRepCocoa& operator=(const ImageRepCocoa&) = delete;
-
-  ~ImageRepCocoa() override {
-    base::mac::NSObjectRelease(image_);
-    image_ = nil;
-  }
-
-  int Width() const override { return Size().width(); }
-
-  int Height() const override { return Size().height(); }
-
-  gfx::Size Size() const override { return internal::NSImageSize(image_); }
-
-  NSImage* image() const { return image_; }
-
- private:
-  NSImage* image_;
-};
-#endif  // BUILDFLAG(IS_MAC)
-
-// The Storage class acts similarly to the pixels in a SkBitmap: the Image
-// class holds a refptr instance of Storage, which in turn holds all the
-// ImageReps. This way, the Image can be cheaply copied.
-//
-// This class is deliberately not RefCountedThreadSafe. Making it so does not
-// solve threading issues, as gfx::Image and its internal classes are
-// themselves not threadsafe.
-class ImageStorage : public base::RefCounted<ImageStorage> {
- public:
-  explicit ImageStorage(Image::RepresentationType default_type)
-      : default_representation_type_(default_type)
+ImageStorage::ImageStorage(Image::RepresentationType default_type)
+    : default_representation_type_(default_type)
 #if BUILDFLAG(IS_MAC)
-        ,
-        default_representation_color_space_(
-            base::mac::GetGenericRGBColorSpace())
+      ,
+      default_representation_color_space_(base::mac::GetGenericRGBColorSpace())
 #endif  // BUILDFLAG(IS_MAC)
-  {
+{
+}
+ImageStorage::~ImageStorage() = default;
+
+Image::RepresentationType ImageStorage::default_representation_type() const {
+  DCHECK(IsOnValidSequence());
+  return default_representation_type_;
+}
+
+bool ImageStorage::HasRepresentation(Image::RepresentationType type) const {
+  DCHECK(IsOnValidSequence());
+  return representations_.count(type) != 0;
+}
+
+size_t ImageStorage::RepresentationCount() const {
+  DCHECK(IsOnValidSequence());
+  return representations_.size();
+}
+
+const ImageRep* ImageStorage::GetRepresentation(
+    Image::RepresentationType rep_type,
+    bool must_exist) const {
+  DCHECK(IsOnValidSequence());
+  auto it = representations_.find(rep_type);
+  if (it == representations_.end()) {
+    CHECK(!must_exist);
+    return nullptr;
   }
+  return it->second.get();
+}
 
-  ImageStorage(const ImageStorage&) = delete;
-  ImageStorage& operator=(const ImageStorage&) = delete;
+const ImageRep* ImageStorage::AddRepresentation(
+    std::unique_ptr<ImageRep> rep) const {
+  DCHECK(IsOnValidSequence());
+  Image::RepresentationType type = rep->type();
+  auto result = representations_.emplace(type, std::move(rep));
 
-  Image::RepresentationType default_representation_type() const {
-    DCHECK(IsOnValidSequence());
-    return default_representation_type_;
-  }
+  // insert should not fail (implies that there was already a representation
+  // of that type in the map).
+  CHECK(result.second) << "type was already in map.";
 
-  bool HasRepresentation(Image::RepresentationType type) const {
-    DCHECK(IsOnValidSequence());
-    return representations_.count(type) != 0;
-  }
-
-  size_t RepresentationCount() const {
-    DCHECK(IsOnValidSequence());
-    return representations_.size();
-  }
-
-  const ImageRep* GetRepresentation(Image::RepresentationType rep_type,
-                                    bool must_exist) const {
-    DCHECK(IsOnValidSequence());
-    RepresentationMap::const_iterator it = representations_.find(rep_type);
-    if (it == representations_.end()) {
-      CHECK(!must_exist);
-      return nullptr;
-    }
-    return it->second.get();
-  }
-
-  const ImageRep* AddRepresentation(std::unique_ptr<ImageRep> rep) const {
-    DCHECK(IsOnValidSequence());
-    Image::RepresentationType type = rep->type();
-    auto result = representations_.emplace(type, std::move(rep));
-
-    // insert should not fail (implies that there was already a representation
-    // of that type in the map).
-    CHECK(result.second) << "type was already in map.";
-
-    return result.first->second.get();
-  }
-
-#if BUILDFLAG(IS_MAC)
-  void set_default_representation_color_space(CGColorSpaceRef color_space) {
-    DCHECK(IsOnValidSequence());
-    default_representation_color_space_ = color_space;
-  }
-  CGColorSpaceRef default_representation_color_space() const {
-    DCHECK(IsOnValidSequence());
-    return default_representation_color_space_;
-  }
-#endif  // BUILDFLAG(IS_MAC)
-
- private:
-  friend class base::RefCounted<ImageStorage>;
-
-  ~ImageStorage() {}
-
-  // The type of image that was passed to the constructor. This key will always
-  // exist in the |representations_| map.
-  Image::RepresentationType default_representation_type_;
-
-#if BUILDFLAG(IS_MAC)
-  // The default representation's colorspace. This is used for converting to
-  // NSImage. This field exists to compensate for PNGCodec not writing or
-  // reading colorspace ancillary chunks. (sRGB, iCCP).
-  // Not owned.
-  CGColorSpaceRef default_representation_color_space_;
-#endif  // BUILDFLAG(IS_MAC)
-
-  // All the representations of an Image. Size will always be at least one, with
-  // more for any converted representations.
-  mutable RepresentationMap representations_;
-};
+  return result.first->second.get();
+}
 
 }  // namespace internal
 
-Image::Image() {
   // |storage_| is null for empty Images.
-}
+Image::Image() = default;
 
 Image::Image(const std::vector<ImagePNGRep>& image_reps) {
   // Do not store obviously invalid ImagePNGReps.
   std::vector<ImagePNGRep> filtered;
-  for (size_t i = 0; i < image_reps.size(); ++i) {
-    if (image_reps[i].raw_data.get() && image_reps[i].raw_data->size())
-      filtered.push_back(image_reps[i]);
+  for (const auto& image_rep : image_reps) {
+    if (image_rep.raw_data.get() && image_rep.raw_data->size())
+      filtered.push_back(image_rep);
   }
 
   if (filtered.empty())
@@ -350,22 +196,6 @@ Image::Image(const ImageSkia& image) {
   }
 }
 
-#if BUILDFLAG(IS_IOS)
-Image::Image(UIImage* image) {
-  if (image) {
-    storage_ = new internal::ImageStorage(Image::kImageRepCocoaTouch);
-    AddRepresentation(std::make_unique<internal::ImageRepCocoaTouch>(image));
-  }
-}
-#elif BUILDFLAG(IS_MAC)
-Image::Image(NSImage* image) {
-  if (image) {
-    storage_ = new internal::ImageStorage(Image::kImageRepCocoa);
-    AddRepresentation(std::make_unique<internal::ImageRepCocoa>(image));
-  }
-}
-#endif
-
 Image::Image(const Image& other) = default;
 
 Image::Image(Image&& other) noexcept = default;
@@ -374,7 +204,7 @@ Image& Image::operator=(const Image& other) = default;
 
 Image& Image::operator=(Image&& other) noexcept = default;
 
-Image::~Image() {}
+Image::~Image() = default;
 
 bool Image::operator==(const Image& other) const {
   return storage_ == other.storage_;
@@ -403,7 +233,7 @@ Image Image::CreateFrom1xPNGBytes(
     return Image();
 
   std::vector<ImagePNGRep> image_reps;
-  image_reps.push_back(ImagePNGRep(input, 1.0f));
+  image_reps.emplace_back(input, 1.0f);
   return Image(image_reps);
 }
 
@@ -430,7 +260,7 @@ const ImageSkia* Image::ToImageSkia() const {
             GetRepresentation(kImageRepCocoaTouch, true)
                 ->AsImageRepCocoaTouch();
         scoped_rep = std::make_unique<internal::ImageRepSkia>(
-            ImageSkia(ImageSkiaFromUIImage(native_rep->image())));
+            ImageSkiaFromUIImage(UIImageOfImageRepCocoaTouch(native_rep)));
         break;
       }
 #elif BUILDFLAG(IS_MAC)
@@ -438,7 +268,7 @@ const ImageSkia* Image::ToImageSkia() const {
         const internal::ImageRepCocoa* native_rep =
             GetRepresentation(kImageRepCocoa, true)->AsImageRepCocoa();
         scoped_rep = std::make_unique<internal::ImageRepSkia>(
-            ImageSkia(ImageSkiaFromNSImage(native_rep->image())));
+            ImageSkiaFromNSImage(NSImageOfImageRepCocoa(native_rep)));
         break;
       }
 #endif
@@ -460,7 +290,7 @@ UIImage* Image::ToUIImage() const {
       case kImageRepPNG: {
         const internal::ImageRepPNG* png_rep =
             GetRepresentation(kImageRepPNG, true)->AsImageRepPNG();
-        scoped_rep = std::make_unique<internal::ImageRepCocoaTouch>(
+        scoped_rep = internal::MakeImageRepCocoaTouch(
             internal::UIImageFromPNG(png_rep->image_reps()));
         break;
       }
@@ -468,7 +298,7 @@ UIImage* Image::ToUIImage() const {
         const internal::ImageRepSkia* skia_rep =
             GetRepresentation(kImageRepSkia, true)->AsImageRepSkia();
         UIImage* image = UIImageFromImageSkia(*skia_rep->image());
-        scoped_rep = std::make_unique<internal::ImageRepCocoaTouch>(image);
+        scoped_rep = internal::MakeImageRepCocoaTouch(image);
         break;
       }
       default:
@@ -477,7 +307,7 @@ UIImage* Image::ToUIImage() const {
     CHECK(scoped_rep);
     rep = AddRepresentation(std::move(scoped_rep));
   }
-  return rep->AsImageRepCocoaTouch()->image();
+  return UIImageOfImageRepCocoaTouch(rep->AsImageRepCocoaTouch());
 }
 #elif BUILDFLAG(IS_MAC)
 NSImage* Image::ToNSImage() const {
@@ -491,9 +321,8 @@ NSImage* Image::ToNSImage() const {
       case kImageRepPNG: {
         const internal::ImageRepPNG* png_rep =
             GetRepresentation(kImageRepPNG, true)->AsImageRepPNG();
-        scoped_rep =
-            std::make_unique<internal::ImageRepCocoa>(internal::NSImageFromPNG(
-                png_rep->image_reps(), default_representation_color_space));
+        scoped_rep = internal::MakeImageRepCocoa(internal::NSImageFromPNG(
+            png_rep->image_reps(), default_representation_color_space));
         break;
       }
       case kImageRepSkia: {
@@ -501,7 +330,7 @@ NSImage* Image::ToNSImage() const {
             GetRepresentation(kImageRepSkia, true)->AsImageRepSkia();
         NSImage* image = NSImageFromImageSkiaWithColorSpace(*skia_rep->image(),
             default_representation_color_space);
-        scoped_rep = std::make_unique<internal::ImageRepCocoa>(image);
+        scoped_rep = internal::MakeImageRepCocoa(image);
         break;
       }
       default:
@@ -510,7 +339,7 @@ NSImage* Image::ToNSImage() const {
     CHECK(scoped_rep);
     rep = AddRepresentation(std::move(scoped_rep));
   }
-  return rep->AsImageRepCocoa()->image();
+  return NSImageOfImageRepCocoa(rep->AsImageRepCocoa());
 }
 #endif
 
@@ -523,9 +352,9 @@ scoped_refptr<base::RefCountedMemory> Image::As1xPNGBytes() const {
   if (rep) {
     const std::vector<ImagePNGRep>& image_png_reps =
         rep->AsImageRepPNG()->image_reps();
-    for (size_t i = 0; i < image_png_reps.size(); ++i) {
-      if (image_png_reps[i].scale == 1.0f)
-        return image_png_reps[i].raw_data;
+    for (const auto& image_png_rep : image_png_reps) {
+      if (image_png_rep.scale == 1.0f)
+        return image_png_rep.raw_data;
     }
     return new base::RefCountedBytes();
   }
@@ -537,14 +366,15 @@ scoped_refptr<base::RefCountedMemory> Image::As1xPNGBytes() const {
       const internal::ImageRepCocoaTouch* cocoa_touch_rep =
           GetRepresentation(kImageRepCocoaTouch, true)->AsImageRepCocoaTouch();
       png_bytes = internal::Get1xPNGBytesFromUIImage(
-          cocoa_touch_rep->image());
+          internal::UIImageOfImageRepCocoaTouch(cocoa_touch_rep));
       break;
     }
 #elif BUILDFLAG(IS_MAC)
     case kImageRepCocoa: {
       const internal::ImageRepCocoa* cocoa_rep =
           GetRepresentation(kImageRepCocoa, true)->AsImageRepCocoa();
-      png_bytes = internal::Get1xPNGBytesFromNSImage(cocoa_rep->image());
+      png_bytes = internal::Get1xPNGBytesFromNSImage(
+          internal::NSImageOfImageRepCocoa(cocoa_rep));
       break;
     }
 #endif
@@ -571,7 +401,7 @@ scoped_refptr<base::RefCountedMemory> Image::As1xPNGBytes() const {
   //   final type eg (converting from ImageRepSkia to ImageRepPNG to get an
   //   ImageRepCocoa).
   std::vector<ImagePNGRep> image_png_reps;
-  image_png_reps.push_back(ImagePNGRep(png_bytes, 1.0f));
+  image_png_reps.emplace_back(png_bytes, 1.0f);
   AddRepresentation(
       base::WrapUnique(new internal::ImageRepPNG(image_png_reps)));
   return png_bytes;

ui/gfx/image/image_internal.h

@@ -0,0 +1,129 @@
+// Copyright 2022 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// This holds internal declarations for the machinery of gfx::Image. These are
+// only for the internal use of gfx::Image; do not use them elsewhere.
+
+#ifndef UI_GFX_IMAGE_IMAGE_INTERNAL_H_
+#define UI_GFX_IMAGE_IMAGE_INTERNAL_H_
+
+#include <map>
+#include <memory>
+
+#include "base/memory/ref_counted.h"
+#include "build/build_config.h"
+#include "ui/gfx/image/image.h"
+
+#if BUILDFLAG(IS_MAC)
+#include <CoreGraphics/CoreGraphics.h>
+#endif
+
+namespace gfx::internal {
+
+class ImageRepPNG;
+class ImageRepSkia;
+class ImageRepCocoa;
+class ImageRepCocoaTouch;
+
+// An ImageRep is the object that holds the backing memory for an Image. Each
+// RepresentationType has an ImageRep subclass that is responsible for freeing
+// the memory that the ImageRep holds. When an ImageRep is created, it expects
+// to take ownership of the image, without having to retain it or increase its
+// reference count.
+class ImageRep {
+ public:
+  ImageRep(const ImageRep&) = delete;
+  ImageRep& operator=(const ImageRep&) = delete;
+
+  // Deletes the associated pixels of an ImageRep.
+  virtual ~ImageRep();
+
+  // Cast helpers ("fake RTTI").
+  const ImageRepPNG* AsImageRepPNG() const;
+  ImageRepPNG* AsImageRepPNG();
+
+  const ImageRepSkia* AsImageRepSkia() const;
+  ImageRepSkia* AsImageRepSkia();
+
+#if BUILDFLAG(IS_IOS)
+  const ImageRepCocoaTouch* AsImageRepCocoaTouch() const;
+  ImageRepCocoaTouch* AsImageRepCocoaTouch();
+#elif BUILDFLAG(IS_MAC)
+  const ImageRepCocoa* AsImageRepCocoa() const;
+  ImageRepCocoa* AsImageRepCocoa();
+#endif
+
+  Image::RepresentationType type() const { return type_; }
+
+  virtual int Width() const = 0;
+  virtual int Height() const = 0;
+  virtual gfx::Size Size() const = 0;
+
+ protected:
+  explicit ImageRep(Image::RepresentationType rep);
+
+ private:
+  Image::RepresentationType type_;
+};
+
+// The Storage class acts similarly to the pixels in a SkBitmap: the Image
+// class holds a refptr instance of Storage, which in turn holds all the
+// ImageReps. This way, the Image can be cheaply copied.
+//
+// This class is deliberately not RefCountedThreadSafe. Making it so does not
+// solve threading issues, as gfx::Image and its internal classes are
+// themselves not threadsafe.
+class ImageStorage : public base::RefCounted<ImageStorage> {
+ public:
+  explicit ImageStorage(Image::RepresentationType default_type);
+
+  ImageStorage(const ImageStorage&) = delete;
+  ImageStorage& operator=(const ImageStorage&) = delete;
+
+  Image::RepresentationType default_representation_type() const;
+  bool HasRepresentation(Image::RepresentationType type) const;
+  size_t RepresentationCount() const;
+
+  const ImageRep* GetRepresentation(Image::RepresentationType rep_type,
+                                    bool must_exist) const;
+  const ImageRep* AddRepresentation(std::unique_ptr<ImageRep> rep) const;
+
+#if BUILDFLAG(IS_MAC)
+  void set_default_representation_color_space(CGColorSpaceRef color_space) {
+    DCHECK(IsOnValidSequence());
+    default_representation_color_space_ = color_space;
+  }
+  CGColorSpaceRef default_representation_color_space() const {
+    DCHECK(IsOnValidSequence());
+    return default_representation_color_space_;
+  }
+#endif  // BUILDFLAG(IS_MAC)
+
+ private:
+  friend class base::RefCounted<ImageStorage>;
+
+  ~ImageStorage();
+
+  // The type of image that was passed to the constructor. This key will always
+  // exist in the |representations_| map.
+  Image::RepresentationType default_representation_type_;
+
+#if BUILDFLAG(IS_MAC)
+  // The default representation's colorspace. This is used for converting to
+  // NSImage. This field exists to compensate for PNGCodec not writing or
+  // reading colorspace ancillary chunks. (sRGB, iCCP).
+  // Not owned.
+  CGColorSpaceRef default_representation_color_space_;
+#endif  // BUILDFLAG(IS_MAC)
+
+  // All the representations of an Image. Size will always be at least one, with
+  // more for any converted representations.
+  mutable std::map<Image::RepresentationType,
+                   std::unique_ptr<internal::ImageRep>>
+      representations_;
+};
+
+}  // namespace gfx::internal
+
+#endif  // UI_GFX_IMAGE_IMAGE_INTERNAL_H_

ui/gfx/image/image_ios.mm

@@ -6,6 +6,7 @@
 
 #include <stddef.h>
 #import <UIKit/UIKit.h>
+
 #include <cmath>
 #include <limits>
 
@@ -13,13 +14,11 @@
 #include "base/mac/scoped_cftyperef.h"
 #include "base/mac/scoped_nsobject.h"
 #include "ui/gfx/geometry/size.h"
+#include "ui/gfx/image/image_internal.h"
 #include "ui/gfx/image/image_png_rep.h"
 #include "ui/gfx/image/image_skia.h"
 #include "ui/gfx/image/image_skia_util_ios.h"
 
-namespace gfx {
-namespace internal {
-
 namespace {
 
 // Returns a 16x16 red UIImage to visually show when a UIImage cannot be
@@ -57,8 +56,51 @@ UIImage* CreateUIImageFromImagePNGRep(const gfx::ImagePNGRep& image_png_rep) {
 
 }  // namespace
 
+namespace gfx {
+
+namespace internal {
+
+class ImageRepCocoaTouch final : public ImageRep {
+ public:
+  explicit ImageRepCocoaTouch(UIImage* image)
+      : ImageRep(Image::kImageRepCocoaTouch),
+        image_(image, base::scoped_policy::RETAIN) {
+    CHECK(image_);
+  }
+
+  ImageRepCocoaTouch(const ImageRepCocoaTouch&) = delete;
+  ImageRepCocoaTouch& operator=(const ImageRepCocoaTouch&) = delete;
+
+  ~ImageRepCocoaTouch() override { image_.reset(); }
+
+  int Width() const override { return Size().width(); }
+
+  int Height() const override { return Size().height(); }
+
+  gfx::Size Size() const override {
+    int width = static_cast<int>(image_.get().size.width);
+    int height = static_cast<int>(image_.get().size.height);
+    return gfx::Size(width, height);
+  }
+
+  UIImage* image() const { return image_; }
+
+ private:
+  base::scoped_nsobject<UIImage> image_;
+};
+
+const ImageRepCocoaTouch* ImageRep::AsImageRepCocoaTouch() const {
+  CHECK_EQ(type_, Image::kImageRepCocoaTouch);
+  return reinterpret_cast<const ImageRepCocoaTouch*>(this);
+}
+ImageRepCocoaTouch* ImageRep::AsImageRepCocoaTouch() {
+  return const_cast<ImageRepCocoaTouch*>(
+      static_cast<const ImageRep*>(this)->AsImageRepCocoaTouch());
+}
+
 scoped_refptr<base::RefCountedMemory> Get1xPNGBytesFromUIImage(
     UIImage* uiimage) {
+  DCHECK(uiimage);
   NSData* data = UIImagePNGRepresentation(uiimage);
 
   if ([data length] == 0)
@@ -113,22 +155,32 @@ ImageSkia ImageSkiaFromPNG(
   // iOS does not expose libpng, so conversion from PNG to ImageSkia must go
   // through UIImage.
   ImageSkia image_skia;
-  for (size_t i = 0; i < image_png_reps.size(); ++i) {
+  for (const auto& image_png_rep : image_png_reps) {
     base::scoped_nsobject<UIImage> uiimage(
-        CreateUIImageFromImagePNGRep(image_png_reps[i]));
-    gfx::ImageSkiaRep image_skia_rep = ImageSkiaRepOfScaleFromUIImage(
-        uiimage, image_png_reps[i].scale);
+        CreateUIImageFromImagePNGRep(image_png_rep));
+    gfx::ImageSkiaRep image_skia_rep =
+        ImageSkiaRepOfScaleFromUIImage(uiimage, image_png_rep.scale);
     if (!image_skia_rep.is_null())
       image_skia.AddRepresentation(image_skia_rep);
   }
   return image_skia;
 }
 
-gfx::Size UIImageSize(UIImage* image) {
-  int width = static_cast<int>(image.size.width);
-  int height = static_cast<int>(image.size.height);
-  return gfx::Size(width, height);
+UIImage* UIImageOfImageRepCocoaTouch(const ImageRepCocoaTouch* image_rep) {
+  return image_rep->image();
 }
 
-} // namespace internal
-} // namespace gfx
+std::unique_ptr<ImageRep> MakeImageRepCocoaTouch(UIImage* image) {
+  return std::make_unique<internal::ImageRepCocoaTouch>(image);
+}
+
+}  // namespace internal
+
+Image::Image(UIImage* image) {
+  if (image) {
+    storage_ = new internal::ImageStorage(Image::kImageRepCocoaTouch);
+    AddRepresentation(std::make_unique<internal::ImageRepCocoaTouch>(image));
+  }
+}
+
+}  // namespace gfx

ui/gfx/image/image_mac.mm

@@ -11,11 +11,9 @@
 #include "base/logging.h"
 #include "base/mac/scoped_nsobject.h"
 #include "ui/gfx/geometry/size.h"
+#include "ui/gfx/image/image_internal.h"
 #include "ui/gfx/image/image_png_rep.h"
 
-namespace gfx {
-namespace internal {
-
 namespace {
 
 // Returns a 16x16 red NSImage to visually show when a NSImage cannot be
@@ -33,10 +31,52 @@ NSImage* GetErrorNSImage() {
 
 }  // namespace
 
+namespace gfx {
+
+namespace internal {
+
+class ImageRepCocoa final : public ImageRep {
+ public:
+  explicit ImageRepCocoa(NSImage* image)
+      : ImageRep(Image::kImageRepCocoa),
+        image_(image, base::scoped_policy::RETAIN) {
+    CHECK(image_);
+  }
+
+  ImageRepCocoa(const ImageRepCocoa&) = delete;
+  ImageRepCocoa& operator=(const ImageRepCocoa&) = delete;
+
+  ~ImageRepCocoa() override { image_.reset(); }
+
+  int Width() const override { return Size().width(); }
+
+  int Height() const override { return Size().height(); }
+
+  gfx::Size Size() const override {
+    int width = static_cast<int>(image_.get().size.width);
+    int height = static_cast<int>(image_.get().size.height);
+    return gfx::Size(width, height);
+  }
+
+  NSImage* image() const { return image_; }
+
+ private:
+  base::scoped_nsobject<NSImage> image_;
+};
+
+const ImageRepCocoa* ImageRep::AsImageRepCocoa() const {
+  CHECK_EQ(type_, Image::kImageRepCocoa);
+  return reinterpret_cast<const ImageRepCocoa*>(this);
+}
+ImageRepCocoa* ImageRep::AsImageRepCocoa() {
+  return const_cast<ImageRepCocoa*>(
+      static_cast<const ImageRep*>(this)->AsImageRepCocoa());
+}
+
 scoped_refptr<base::RefCountedMemory> Get1xPNGBytesFromNSImage(
     NSImage* nsimage) {
   DCHECK(nsimage);
-  CGImageRef cg_image = [nsimage CGImageForProposedRect:NULL
+  CGImageRef cg_image = [nsimage CGImageForProposedRect:nullptr
                                                 context:nil
                                                   hints:nil];
   if (!cg_image) {
@@ -64,17 +104,15 @@ NSImage* NSImageFromPNG(const std::vector<gfx::ImagePNGRep>& image_png_reps,
   }
 
   base::scoped_nsobject<NSImage> image;
-  for (size_t i = 0; i < image_png_reps.size(); ++i) {
-    scoped_refptr<base::RefCountedMemory> png = image_png_reps[i].raw_data;
+  for (const auto& image_png_rep : image_png_reps) {
+    scoped_refptr<base::RefCountedMemory> png = image_png_rep.raw_data;
     CHECK(png.get());
     base::scoped_nsobject<NSData> ns_data(
         [[NSData alloc] initWithBytes:png->front() length:png->size()]);
     base::scoped_nsobject<NSBitmapImageRep> ns_image_rep(
         [[NSBitmapImageRep alloc] initWithData:ns_data]);
     if (!ns_image_rep) {
-      LOG(ERROR) << "Unable to decode PNG at "
-                 << image_png_reps[i].scale
-                 << ".";
+      LOG(ERROR) << "Unable to decode PNG at " << image_png_rep.scale << ".";
       return GetErrorNSImage();
     }
 
@@ -96,7 +134,7 @@ NSImage* NSImageFromPNG(const std::vector<gfx::ImagePNGRep>& image_png_reps,
     }
 
     if (!image.get()) {
-      float scale = image_png_reps[i].scale;
+      float scale = image_png_rep.scale;
       NSSize image_size = NSMakeSize([ns_image_rep pixelsWide] / scale,
                                      [ns_image_rep pixelsHigh] / scale);
       image.reset([[NSImage alloc] initWithSize:image_size]);
@@ -107,13 +145,21 @@ NSImage* NSImageFromPNG(const std::vector<gfx::ImagePNGRep>& image_png_reps,
   return image.autorelease();
 }
 
-gfx::Size NSImageSize(NSImage* image) {
-  NSSize size = [image size];
-  int width = static_cast<int>(size.width);
-  int height = static_cast<int>(size.height);
-  return gfx::Size(width, height);
+NSImage* NSImageOfImageRepCocoa(const ImageRepCocoa* image_rep) {
+  return image_rep->image();
 }
 
-} // namespace internal
-} // namespace gfx
+std::unique_ptr<ImageRep> MakeImageRepCocoa(NSImage* image) {
+  return std::make_unique<internal::ImageRepCocoa>(image);
+}
 
+}  // namespace internal
+
+Image::Image(NSImage* image) {
+  if (image) {
+    storage_ = new internal::ImageStorage(Image::kImageRepCocoa);
+    AddRepresentation(std::make_unique<internal::ImageRepCocoa>(image));
+  }
+}
+
+}  // namespace gfx

ui/gfx/image/image_platform.h

@@ -30,27 +30,33 @@
 #include "ui/gfx/image/image_skia_util_mac.h"
 #endif
 
-namespace gfx {
-namespace internal {
+namespace gfx::internal {
+
+class ImageRep;
+class ImageRepCocoa;
+class ImageRepCocoaTouch;
 
 #if BUILDFLAG(IS_IOS)
 scoped_refptr<base::RefCountedMemory> Get1xPNGBytesFromUIImage(
     UIImage* uiimage);
 UIImage* UIImageFromPNG(const std::vector<ImagePNGRep>& image_png_reps);
-gfx::Size UIImageSize(UIImage* image);
+
+UIImage* UIImageOfImageRepCocoaTouch(const ImageRepCocoaTouch* image_rep);
+std::unique_ptr<ImageRep> MakeImageRepCocoaTouch(UIImage* image);
 #elif BUILDFLAG(IS_MAC)
 scoped_refptr<base::RefCountedMemory> Get1xPNGBytesFromNSImage(
     NSImage* nsimage);
 NSImage* NSImageFromPNG(const std::vector<ImagePNGRep>& image_png_reps,
                         CGColorSpaceRef color_space);
-gfx::Size NSImageSize(NSImage* image);
+
+NSImage* NSImageOfImageRepCocoa(const ImageRepCocoa* image_rep);
+std::unique_ptr<ImageRep> MakeImageRepCocoa(NSImage* image);
 #endif
 
 ImageSkia ImageSkiaFromPNG(const std::vector<ImagePNGRep>& image_png_reps);
 scoped_refptr<base::RefCountedMemory> Get1xPNGBytesFromImageSkia(
     const ImageSkia* image_skia);
 
-}  // namespace internal
-}  // namespace gfx
+}  // namespace gfx::internal
 
 #endif  // UI_GFX_IMAGE_IMAGE_PLATFORM_H_