Allow to have a transparent UA dependent background.

content/browser/renderer_host/render_widget_host_view_base.cc

 // Copyright (c) 2012 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.
 
 #include "content/browser/renderer_host/render_widget_host_view_base.h"
 
 #include "base/logging.h"
 #include "build/build_config.h"
 #include "content/browser/accessibility/browser_accessibility_manager.h"
 #include "content/browser/gpu/gpu_data_manager_impl.h"
@@ skipping 353 matching lines @@
 namespace {
 
 // How many microseconds apart input events should be flushed.
 const int kFlushInputRateInUs = 16666;
 
 }
 
 RenderWidgetHostViewBase::RenderWidgetHostViewBase()
     : popup_type_(blink::WebPopupTypeNone),
       background_color_(SK_ColorWHITE),
+      background_opaque_(false),
       mouse_locked_(false),
       showing_context_menu_(false),
       selection_text_offset_(0),
       selection_range_(gfx::Range::InvalidRange()),
       current_device_scale_factor_(0),
       current_display_rotation_(gfx::Display::ROTATE_0),
       pinch_zoom_enabled_(content::IsPinchToZoomEnabled()),
       renderer_frame_number_(0),
       weak_factory_(this) {}
 
@@ skipping 24 matching lines @@
 }
 
 void RenderWidgetHostViewBase::SetBackgroundColor(SkColor color) {
   background_color_ = color;
 }
 
 void RenderWidgetHostViewBase::SetBackgroundColorToDefault() {
   SetBackgroundColor(SK_ColorWHITE);
 }
 
+void RenderWidgetHostViewBase::SetBackgroundOpaque(bool opaque) {
+  background_opaque_ = opaque;
+}
+
 bool RenderWidgetHostViewBase::GetBackgroundOpaque() {
-  return SkColorGetA(background_color_) == SK_AlphaOPAQUE;
+  return background_opaque_;
 }
 
 gfx::Size RenderWidgetHostViewBase::GetPhysicalBackingSize() const {
   gfx::Display display =
       gfx::Screen::GetScreen()->GetDisplayNearestWindow(GetNativeView());
   return gfx::ScaleToCeiledSize(GetRequestedRendererSize(),
                                 display.device_scale_factor());
 }
 
 bool RenderWidgetHostViewBase::DoTopControlsShrinkBlinkSize() const {
@@ skipping 298 matching lines @@
 void RenderWidgetHostViewBase::RemoveObserver(
     RenderWidgetHostViewBaseObserver* observer) {
   observers_.RemoveObserver(observer);
 }
 
 cc::SurfaceId RenderWidgetHostViewBase::SurfaceIdForTesting() const {
   return cc::SurfaceId();
 }
 
 }  // namespace content