Remove PPAPI dependency by adding a pp::Var to base::Value converter

This change removes the pp::Var dependency from core PDF code by
converting the incoming pp::Var data to base::Value and updating the
core PDF code to work with base::Value instead of pp::Var.

The pp::Var types of PP_VARTYPE_OBJECT and PP_VARTYPE_RESOURCE do not
have any valid conversion to base::Value and hence have added
NOTREACHED() in those cases.

Bug: 1094049
Change-Id: I3f6e54b04878e10d0d0ae860a6b1e8446e7e04e1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2413707
Commit-Queue: Gourab Kundu <gourabk@microsoft.com>
Reviewed-by: Lei Zhang <thestig@chromium.org>
Reviewed-by: K. Moon <kmoon@chromium.org>
Reviewed-by: Ankit Kumar 🌪️ <ankk@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#809692}

pdf/document_layout.cc

@@ -8,8 +8,6 @@
 
 #include "base/check_op.h"
 #include "base/values.h"
-#include "ppapi/cpp/var.h"
-#include "ppapi/cpp/var_dictionary.h"
 #include "ui/gfx/geometry/point.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/geometry/size.h"
@@ -59,11 +57,11 @@ base::Value DocumentLayout::Options::ToValue() const {
   return dictionary;
 }
 
-void DocumentLayout::Options::FromVar(const pp::Var& var) {
-  pp::VarDictionary dictionary(var);
+void DocumentLayout::Options::FromValue(const base::Value& value) {
+  DCHECK(value.is_dict());
 
   int32_t default_page_orientation =
-      dictionary.Get(kDefaultPageOrientation).AsInt();
+      value.FindKey(kDefaultPageOrientation)->GetInt();
   DCHECK_GE(default_page_orientation,
             static_cast<int32_t>(PageOrientation::kOriginal));
   DCHECK_LE(default_page_orientation,
@@ -71,7 +69,7 @@ void DocumentLayout::Options::FromVar(const pp::Var& var) {
   default_page_orientation_ =
       static_cast<PageOrientation>(default_page_orientation);
 
-  two_up_view_enabled_ = dictionary.Get(kTwoUpViewEnabled).AsBool();
+  two_up_view_enabled_ = value.FindKey(kTwoUpViewEnabled)->GetBool();
 }
 
 void DocumentLayout::Options::RotatePagesClockwise() {

pdf/document_layout.h

@@ -18,10 +18,6 @@ namespace base {
 class Value;
 }
 
-namespace pp {
-class Var;
-}  // namespace pp
-
 namespace chrome_pdf {
 
 // Layout of pages within a PDF document. Pages are placed as rectangles
@@ -55,8 +51,8 @@ class DocumentLayout final {
     // Serializes layout options to a base::Value.
     base::Value ToValue() const;
 
-    // Deserializes layout options from a pp::Var.
-    void FromVar(const pp::Var& var);
+    // Deserializes layout options from a base::Value.
+    void FromValue(const base::Value& value);
 
     PageOrientation default_page_orientation() const {
       return default_page_orientation_;

pdf/out_of_process_instance.cc

@@ -1833,7 +1833,7 @@ void OutOfProcessInstance::HandleViewportMessage(
   pp::Var layout_options_var = dict.Get(kJSLayoutOptions);
   if (!layout_options_var.is_undefined()) {
     DocumentLayout::Options layout_options;
-    layout_options.FromVar(layout_options_var);
+    layout_options.FromValue(ValueFromVar(layout_options_var));
     // TODO(crbug.com/1013800): Eliminate need to get document size from here.
     document_size_ =
         PPSizeFromSize(engine()->ApplyDocumentLayout(layout_options));

pdf/ppapi_migration/value_conversions.cc

@@ -6,6 +6,8 @@
 
 #include <algorithm>
 
+#include "base/containers/span.h"
+#include "base/notreached.h"
 #include "base/values.h"
 #include "ppapi/cpp/var.h"
 #include "ppapi/cpp/var_array.h"
@@ -55,4 +57,57 @@ pp::Var VarFromValue(const base::Value& value) {
   }
 }
 
-}  // namespace chrome_pdf
+base::Value ValueFromVar(const pp::Var& var) {
+  switch (var.pp_var().type) {
+    case PP_VARTYPE_UNDEFINED:
+      return base::Value();
+    case PP_VARTYPE_NULL:
+      return base::Value();
+    case PP_VARTYPE_BOOL:
+      return base::Value(var.AsBool());
+    case PP_VARTYPE_INT32:
+      return base::Value(var.AsInt());
+    case PP_VARTYPE_DOUBLE:
+      return base::Value(var.AsDouble());
+    case PP_VARTYPE_STRING:
+      return base::Value(var.AsString());
+    case PP_VARTYPE_OBJECT:
+      // There is no valid conversion from PP_VARTYPE_OBJECT to a base::Value
+      // type. This should not be called to convert this type.
+      NOTREACHED();
+      return base::Value();
+    case PP_VARTYPE_ARRAY: {
+      pp::VarArray var_array(var);
+      base::Value::ListStorage list_storage(var_array.GetLength());
+      for (uint32_t i = 0; i < var_array.GetLength(); ++i) {
+        list_storage[i] = ValueFromVar(var_array.Get(i));
+      }
+      return base::Value(std::move(list_storage));
+    }
+    case PP_VARTYPE_DICTIONARY: {
+      base::Value val_dictionary(base::Value::Type::DICTIONARY);
+      pp::VarDictionary var_dict(var);
+      pp::VarArray dict_keys = var_dict.GetKeys();
+      for (uint32_t i = 0; i < dict_keys.GetLength(); ++i) {
+        pp::Var key = dict_keys.Get(i);
+        val_dictionary.SetKey(key.AsString(), ValueFromVar(var_dict.Get(key)));
+      }
+      return val_dictionary;
+    }
+    case PP_VARTYPE_ARRAY_BUFFER: {
+      pp::VarArrayBuffer var_array_buffer(var);
+      base::Value value(
+          base::make_span(static_cast<uint8_t*>(var_array_buffer.Map()),
+                          var_array_buffer.ByteLength()));
+      var_array_buffer.Unmap();
+      return value;
+    }
+    case PP_VARTYPE_RESOURCE:
+      // There is no valid conversion from PP_VARTYPE_RESOURCE to a base::Value
+      // type. This should not be called to convert this type.
+      NOTREACHED();
+      return base::Value();
+  }
+}
+
+}  // namespace chrome_pdf

pdf/ppapi_migration/value_conversions.h

@@ -16,7 +16,8 @@ class Var;
 namespace chrome_pdf {
 
 pp::Var VarFromValue(const base::Value& value);
+base::Value ValueFromVar(const pp::Var& var);
 
 }  // namespace chrome_pdf
 
-#endif  // PDF_PPAPI_MIGRATION_VALUE_CONVERSIONS_H_
+#endif  // PDF_PPAPI_MIGRATION_VALUE_CONVERSIONS_H_