Code refactor in PdfAccessibilityTree

This CL does code refactoring to make the intent of PdfAccessibilityTree
.zoom variable clear. It stores the product of pdf zoom and system dpi.
This change renames it to zoom_device_scale_factor.

This change also refactors the zoom variable name in
PP_PrivateAccessibilityViewportInfo to zoom_device_scale_factor.

Corresponding change is also made in OutOfProcessInstance to reflect
the variable name change.

Bug: 1007169
Change-Id: I0a9c22f386fb4859afc80d9f281f41a15935bb09
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1823337Reviewed-by: Jochen Eisinger <jochen@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Ian Prest <iapres@microsoft.com>
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Virender Singh <virens@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#705947}

components/pdf/renderer/pdf_accessibility_tree.cc

@@ -208,13 +208,9 @@ bool IsObjectInTextRun(const std::vector<T>& objects,
 
 }  // namespace
 
-PdfAccessibilityTree::PdfAccessibilityTree(
-    content::RendererPpapiHost* host,
-    PP_Instance instance)
-    : host_(host),
-      instance_(instance),
-      zoom_(1.0) {
-}
+PdfAccessibilityTree::PdfAccessibilityTree(content::RendererPpapiHost* host,
+                                           PP_Instance instance)
+    : host_(host), instance_(instance) {}
 
 PdfAccessibilityTree::~PdfAccessibilityTree() {
   content::RenderAccessibility* render_accessibility = GetRenderAccessibility();
@@ -265,12 +261,12 @@ bool PdfAccessibilityTree::IsDataFromPluginValid(
 
 void PdfAccessibilityTree::SetAccessibilityViewportInfo(
     const PP_PrivateAccessibilityViewportInfo& viewport_info) {
-  zoom_ = viewport_info.zoom;
-  CHECK_GT(zoom_, 0);
+  zoom_device_scale_factor_ = viewport_info.zoom_device_scale_factor;
+  CHECK_GT(zoom_device_scale_factor_, 0);
   scroll_ = ToVector2dF(viewport_info.scroll);
-  scroll_.Scale(1.0 / zoom_);
+  scroll_.Scale(1.0 / zoom_device_scale_factor_);
   offset_ = ToVector2dF(viewport_info.offset);
-  offset_.Scale(1.0 / zoom_);
+  offset_.Scale(1.0 / zoom_device_scale_factor_);
 
   selection_start_page_index_ = viewport_info.selection_start_page_index;
   selection_start_char_index_ = viewport_info.selection_start_char_index;
@@ -830,7 +826,7 @@ content::RenderAccessibility* PdfAccessibilityTree::GetRenderAccessibility() {
 
 gfx::Transform* PdfAccessibilityTree::MakeTransformFromViewInfo() {
   gfx::Transform* transform = new gfx::Transform();
-  float scale_factor = zoom_ / GetDeviceScaleFactor();
+  float scale_factor = zoom_device_scale_factor_ / GetDeviceScaleFactor();
   transform->Scale(scale_factor, scale_factor);
   transform->Translate(offset_);
   transform->Translate(-scroll_);

components/pdf/renderer/pdf_accessibility_tree.h

@@ -164,7 +164,7 @@ class PdfAccessibilityTree : public content::PluginAXTreeSource {
   ui::AXTree tree_;
   content::RendererPpapiHost* host_;
   PP_Instance instance_;
-  double zoom_;
+  double zoom_device_scale_factor_ = 1.0;
   gfx::Vector2dF scroll_;
   gfx::Vector2dF offset_;
   uint32_t selection_start_page_index_ = 0;

components/pdf/renderer/pdf_accessibility_tree_browsertest.cc

@@ -157,7 +157,7 @@ class PdfAccessibilityTreeTest : public content::RenderViewTest {
     ui::ResourceBundle::GetSharedInstance().AddDataPackFromPath(
         pak_file, ui::SCALE_FACTOR_NONE);
 
-    viewport_info_.zoom = 1.0;
+    viewport_info_.zoom_device_scale_factor = 1.0;
     viewport_info_.scroll = {0, 0};
     viewport_info_.offset = {0, 0};
     viewport_info_.selection_start_page_index = 0;

pdf/out_of_process_instance.cc

@@ -995,7 +995,7 @@ void OutOfProcessInstance::SendAccessibilityViewportInfo() {
   viewport_info.scroll.y =
       -top_toolbar_height_in_viewport_coords_ * device_scale_;
   viewport_info.offset = available_area_.point();
-  viewport_info.zoom = zoom_ * device_scale_;
+  viewport_info.zoom_device_scale_factor = zoom_ * device_scale_;
 
   engine_->GetSelection(&viewport_info.selection_start_page_index,
                         &viewport_info.selection_start_char_index,

ppapi/c/private/ppb_pdf.h

@@ -34,7 +34,7 @@ struct PP_PrivateFindResult {
 };
 
 struct PP_PrivateAccessibilityViewportInfo {
-  double zoom;
+  double zoom_device_scale_factor;
   struct PP_Point scroll;
   struct PP_Point offset;
   uint32_t selection_start_page_index;

ppapi/proxy/ppapi_messages.h

@@ -255,7 +255,7 @@ IPC_STRUCT_TRAITS_BEGIN(PP_PdfPrintSettings_Dev)
 IPC_STRUCT_TRAITS_END()
 
 IPC_STRUCT_TRAITS_BEGIN(PP_PrivateAccessibilityViewportInfo)
-  IPC_STRUCT_TRAITS_MEMBER(zoom)
+  IPC_STRUCT_TRAITS_MEMBER(zoom_device_scale_factor)
   IPC_STRUCT_TRAITS_MEMBER(scroll)
   IPC_STRUCT_TRAITS_MEMBER(offset)
   IPC_STRUCT_TRAITS_MEMBER(selection_start_page_index)