Reland "Add annotation structs for PDF accessibility"

This is a reland of 4389c2c30c

This change was reverted due to "Windows Deterministic" bot failing. These bots
seems to have a problem with any changes to ppapi/. I am suppressing the errors
in CL:1924340.

This is the exact same CL as the one that was reverted.

Original change's description:
> Add annotation structs for PDF accessibility
>
> This change adds new *AccessibilityAnnotInfo structs to transfer
> accessibility related PDF annotation data from the plugin process up to
> the mimehandler process via the pepper API. This annotation information
> is bundled along with links and images into the
> *AccessibilityPageObjects group of structs introduced as a part of
> http://crrev.com/c/1831957. It will be populated from within pdfium_page
> in a subsequent change.
>
> Bug: 1008775
> Change-Id: I89eabc8f56c135eac95c2c887d33854fbccbbcb7
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1837558
> Reviewed-by: Daniel Cheng <dcheng@chromium.org>
> Reviewed-by: Lei Zhang <thestig@chromium.org>
> Reviewed-by: Kevin Babbitt <kbabbitt@microsoft.com>
> Reviewed-by: Bill Budge <bbudge@chromium.org>
> Reviewed-by: Ian Prest <iapres@microsoft.com>
> Commit-Queue: Kalpak Tapas <katapas@microsoft.com>
> Cr-Commit-Position: refs/heads/master@{#716555}

TBR=dcheng@chromium.org,kbabbitt@microsoft.com,bbudge@chromium.org,
iapres@microsoft.com

Bug: 1008775
Change-Id: I6fa8d63e81076dae291ccc74cd9a32e5eb78078d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1926107
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Ankit Kumar 🌪️ <ankk@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#718075}

pdf/accessibility.cc

@@ -191,6 +191,7 @@ bool GetAccessibilityInfo(
                            &page_objects->links);
   GetAccessibilityImageInfo(engine, page_index, page_info->text_run_count,
                             &page_objects->images);
+  // TODO(crbug.com/1008775): Populate highlights
   return true;
 }
 

ppapi/c/private/ppb_pdf.h

@@ -149,7 +149,29 @@ struct PP_PrivateAccessibilityImageInfo {
   struct PP_FloatRect bounds;
 };
 
-// Holds links and images within a PDF page so that IPC messages
+// This holds text highlight information provided by the PDF and will be
+// used in accessibility to expose it. Text highlights can have an associated
+// popup note, the data of which is also captured here.
+// Needs to stay in sync with C++ versions (PdfAccessibilityHighlightInfo and
+// PrivateAccessibilityHighlightInfo).
+struct PP_PrivateAccessibilityHighlightInfo {
+  // Represents the text of the associated popup note, if present.
+  const char* note_text;
+  uint32_t note_text_length;
+  // Index of the highlight in the page annotation list. Used to identify the
+  // annotation on which action needs to be performed.
+  uint32_t index_in_page;
+  // Highlights are annotations over existing page text.  |text_run_index|
+  // denotes the index of the text run where the highlight starts and
+  // |text_run_count| denotes the number of text runs which the highlight spans
+  // across.
+  uint32_t text_run_index;
+  uint32_t text_run_count;
+  // Bounding box of the highlight.
+  struct PP_FloatRect bounds;
+};
+
+// Holds links, images and highlights within a PDF page so that IPC messages
 // passing accessibility objects do not have too many parameters.
 // Needs to stay in sync with C++ versions (PdfAccessibilityPageObjects and
 // PrivateAccessibilityPageObjects).
@@ -158,6 +180,8 @@ struct PP_PrivateAccessibilityPageObjects {
   uint32_t link_count;
   struct PP_PrivateAccessibilityImageInfo* images;
   uint32_t image_count;
+  struct PP_PrivateAccessibilityHighlightInfo* highlights;
+  uint32_t highlight_count;
 };
 
 struct PPB_PDF {

ppapi/cpp/private/pdf.cc

@@ -61,6 +61,17 @@ void ConvertPrivateAccessibilityImageInfo(
   info->bounds = image.bounds;
 }
 
+void ConvertPrivateAccessibilityHighlightInfo(
+    const PDF::PrivateAccessibilityHighlightInfo& highlight,
+    PP_PrivateAccessibilityHighlightInfo* info) {
+  info->note_text = highlight.note_text.c_str();
+  info->note_text_length = highlight.note_text.size();
+  info->index_in_page = highlight.index_in_page;
+  info->text_run_index = highlight.text_run_index;
+  info->text_run_count = highlight.text_run_count;
+  info->bounds = highlight.bounds;
+}
+
 }  // namespace
 
 // static
@@ -262,11 +273,22 @@ void PDF::SetAccessibilityPageInfo(
     for (size_t i = 0; i < images.size(); ++i)
       ConvertPrivateAccessibilityImageInfo(images[i], &image_info[i]);
 
+    const std::vector<PrivateAccessibilityHighlightInfo>& highlights =
+        page_objects.highlights;
+    std::vector<PP_PrivateAccessibilityHighlightInfo> highlight_info(
+        highlights.size());
+    for (size_t i = 0; i < highlights.size(); ++i) {
+      ConvertPrivateAccessibilityHighlightInfo(highlights[i],
+                                               &highlight_info[i]);
+    }
+
     PP_PrivateAccessibilityPageObjects pp_page_objects;
     pp_page_objects.links = link_info.data();
     pp_page_objects.link_count = link_info.size();
     pp_page_objects.images = image_info.data();
     pp_page_objects.image_count = image_info.size();
+    pp_page_objects.highlights = highlight_info.data();
+    pp_page_objects.highlight_count = highlight_info.size();
 
     get_interface<PPB_PDF>()->SetAccessibilityPageInfo(
         instance.pp_instance(), page_info, text_run_info.data(), chars.data(),

ppapi/cpp/private/pdf.h

@@ -49,7 +49,10 @@ class PDF {
   // Needs to stay in sync with the C version.
   struct PrivateAccessibilityLinkInfo {
     std::string url;
+    // Index of this link in the collection of links in the page.
     uint32_t index_in_page;
+    // Index of the starting text run of this link in the collection of all
+    // text runs in the page.
     uint32_t text_run_index;
     uint32_t text_run_count;
     FloatRect bounds;
@@ -63,11 +66,25 @@ class PDF {
     FloatRect bounds;
   };
 
+  // C++ version of PP_PrivateAccessibilityHighlightInfo.
+  // Needs to stay in sync with the C version.
+  struct PrivateAccessibilityHighlightInfo {
+    std::string note_text;
+    // Index of this highlight in the collection of highlights in the page.
+    uint32_t index_in_page;
+    // Index of the starting text run of this highlight in the collection of all
+    // text runs in the page.
+    uint32_t text_run_index;
+    uint32_t text_run_count;
+    FloatRect bounds;
+  };
+
   // C++ version of PP_PrivateAccessibilityPageObjects.
   // Needs to stay in sync with the C version.
   struct PrivateAccessibilityPageObjects {
     std::vector<PrivateAccessibilityLinkInfo> links;
     std::vector<PrivateAccessibilityImageInfo> images;
+    std::vector<PrivateAccessibilityHighlightInfo> highlights;
   };
 
   // Returns true if the required interface is available.

ppapi/proxy/pdf_resource.cc

@@ -236,10 +236,16 @@ void PDFResource::SetAccessibilityPageInfo(
   for (size_t i = 0; i < page_objects->image_count; i++) {
     image_vector.emplace_back(page_objects->images[i]);
   }
+  std::vector<ppapi::PdfAccessibilityHighlightInfo> highlight_vector;
+  highlight_vector.reserve(page_objects->highlight_count);
+  for (size_t i = 0; i < page_objects->highlight_count; i++) {
+    highlight_vector.emplace_back(page_objects->highlights[i]);
+  }
 
   ppapi::PdfAccessibilityPageObjects ppapi_page_objects;
   ppapi_page_objects.links = std::move(link_vector);
   ppapi_page_objects.images = std::move(image_vector);
+  ppapi_page_objects.highlights = std::move(highlight_vector);
 
   Post(RENDERER,
        PpapiHostMsg_PDF_SetAccessibilityPageInfo(

ppapi/proxy/ppapi_messages.h

@@ -314,9 +314,18 @@ IPC_STRUCT_TRAITS_BEGIN(ppapi::PdfAccessibilityImageInfo)
   IPC_STRUCT_TRAITS_MEMBER(bounds)
 IPC_STRUCT_TRAITS_END()
 
+IPC_STRUCT_TRAITS_BEGIN(ppapi::PdfAccessibilityHighlightInfo)
+  IPC_STRUCT_TRAITS_MEMBER(note_text)
+  IPC_STRUCT_TRAITS_MEMBER(index_in_page)
+  IPC_STRUCT_TRAITS_MEMBER(text_run_index)
+  IPC_STRUCT_TRAITS_MEMBER(text_run_count)
+  IPC_STRUCT_TRAITS_MEMBER(bounds)
+IPC_STRUCT_TRAITS_END()
+
 IPC_STRUCT_TRAITS_BEGIN(ppapi::PdfAccessibilityPageObjects)
   IPC_STRUCT_TRAITS_MEMBER(links)
   IPC_STRUCT_TRAITS_MEMBER(images)
+  IPC_STRUCT_TRAITS_MEMBER(highlights)
 IPC_STRUCT_TRAITS_END()
 
 IPC_STRUCT_TRAITS_BEGIN(PP_URLComponent_Dev)

ppapi/shared_impl/pdf_accessibility_shared.cc

@@ -60,6 +60,18 @@ PdfAccessibilityImageInfo::PdfAccessibilityImageInfo(
 
 PdfAccessibilityImageInfo::~PdfAccessibilityImageInfo() = default;
 
+PdfAccessibilityHighlightInfo::PdfAccessibilityHighlightInfo() = default;
+
+PdfAccessibilityHighlightInfo::~PdfAccessibilityHighlightInfo() = default;
+
+PdfAccessibilityHighlightInfo::PdfAccessibilityHighlightInfo(
+    const PP_PrivateAccessibilityHighlightInfo& highlight)
+    : note_text(std::string(highlight.note_text, highlight.note_text_length)),
+      index_in_page(highlight.index_in_page),
+      text_run_index(highlight.text_run_index),
+      text_run_count(highlight.text_run_count),
+      bounds(highlight.bounds) {}
+
 PdfAccessibilityPageObjects::PdfAccessibilityPageObjects() = default;
 
 PdfAccessibilityPageObjects::PdfAccessibilityPageObjects(
@@ -73,6 +85,11 @@ PdfAccessibilityPageObjects::PdfAccessibilityPageObjects(
   for (size_t i = 0; i < page_objects.image_count; i++) {
     images.emplace_back(page_objects.images[i]);
   }
+
+  highlights.reserve(page_objects.highlight_count);
+  for (size_t i = 0; i < page_objects.highlight_count; i++) {
+    highlights.emplace_back(page_objects.highlights[i]);
+  }
 }
 
 PdfAccessibilityPageObjects::~PdfAccessibilityPageObjects() = default;

ppapi/shared_impl/pdf_accessibility_shared.h

@@ -75,6 +75,20 @@ struct PPAPI_SHARED_EXPORT PdfAccessibilityImageInfo {
   PP_FloatRect bounds;
 };
 
+// Needs to stay in sync with PP_PrivateAccessibilityHighlightInfo.
+struct PPAPI_SHARED_EXPORT PdfAccessibilityHighlightInfo {
+  PdfAccessibilityHighlightInfo();
+  explicit PdfAccessibilityHighlightInfo(
+      const PP_PrivateAccessibilityHighlightInfo& highlight);
+  ~PdfAccessibilityHighlightInfo();
+
+  std::string note_text;
+  uint32_t index_in_page;
+  uint32_t text_run_index;
+  uint32_t text_run_count;
+  PP_FloatRect bounds;
+};
+
 // Needs to stay in sync with PP_PrivateAccessibilityPageObjects.
 struct PPAPI_SHARED_EXPORT PdfAccessibilityPageObjects {
   PdfAccessibilityPageObjects();
@@ -84,6 +98,7 @@ struct PPAPI_SHARED_EXPORT PdfAccessibilityPageObjects {
 
   std::vector<PdfAccessibilityLinkInfo> links;
   std::vector<PdfAccessibilityImageInfo> images;
+  std::vector<PdfAccessibilityHighlightInfo> highlights;
 };
 
 }  // namespace ppapi