Mac: Remove white CALayers

content/browser/renderer_host/render_widget_host_view_mac.mm

 // 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_mac.h"
 
 #import <Carbon/Carbon.h>
 #import <objc/runtime.h>
 #include <OpenGL/gl.h>
 #include <QuartzCore/QuartzCore.h>
@@ skipping 424 matching lines @@
 
 RenderWidgetHostViewMac::RenderWidgetHostViewMac(RenderWidgetHost* widget,
                                                  bool is_guest_view_hack)
     : render_widget_host_(RenderWidgetHostImpl::From(widget)),
       page_at_minimum_scale_(true),
       is_loading_(false),
       allow_pause_for_resize_or_repaint_(true),
       is_guest_view_hack_(is_guest_view_hack),
       fullscreen_parent_host_view_(nullptr),
       needs_flush_input_(false),
-      background_color_(SK_ColorWHITE),
       weak_factory_(this) {
   // |cocoa_view_| owns us and we will be deleted when |cocoa_view_|
   // goes away.  Since we autorelease it, our caller must put
   // |GetNativeView()| into the view hierarchy right after calling us.
   cocoa_view_ = [[[RenderWidgetHostViewCocoa alloc]
                   initWithRenderWidgetHostViewMac:this] autorelease];
 
-  // Paint this view host with |background_color_| when there is no content
-  // ready to draw.
   background_layer_.reset([[CALayer alloc] init]);
-  // Set the default color to be white. This is the wrong thing to do, but many
-  // UI components expect this view to be opaque.
-  [background_layer_ setBackgroundColor:CGColorGetConstantColor(kCGColorWhite)];
   [cocoa_view_ setLayer:background_layer_];
   [cocoa_view_ setWantsLayer:YES];
 
   cc::FrameSinkId frame_sink_id =
       render_widget_host_->AllocateFrameSinkId(is_guest_view_hack_);
   browser_compositor_.reset(
       new BrowserCompositorMac(this, this, render_widget_host_->is_hidden(),
                                [cocoa_view_ window], frame_sink_id));
 
   display::Screen::GetScreen()->AddObserver(this);
@@ skipping 1163 matching lines @@
   if (!active)
     UnlockMouse();
 }
 
 void RenderWidgetHostViewMac::ShowDefinitionForSelection() {
   RenderWidgetHostViewMacDictionaryHelper helper(this);
   helper.ShowDefinitionForSelection();
 }
 
 void RenderWidgetHostViewMac::SetBackgroundColor(SkColor color) {
+  if (color == background_color_)
+    return;
+
   // The renderer will feed its color back to us with the first CompositorFrame.
   // We short-cut here to show a sensible color before that happens.
   UpdateBackgroundColorFromRenderer(color);
 
   DCHECK(SkColorGetA(color) == SK_AlphaOPAQUE ||
          SkColorGetA(color) == SK_AlphaTRANSPARENT);
   bool opaque = SkColorGetA(color) == SK_AlphaOPAQUE;
   if (render_widget_host_)
     render_widget_host_->SetBackgroundOpaque(opaque);
 }
 
 SkColor RenderWidgetHostViewMac::background_color() const {
   return background_color_;
 }
 
 void RenderWidgetHostViewMac::UpdateBackgroundColorFromRenderer(SkColor color) {
-  if (color == background_color())
+  if (color == background_color_)
     return;
   background_color_ = color;
 
   bool opaque = SkColorGetA(color) == SK_AlphaOPAQUE;
 
   [cocoa_view_ setOpaque:opaque];
 
   browser_compositor_->SetHasTransparentBackground(!opaque);
 
   ScopedCAActionDisabler disabler;
@@ skipping 91 matching lines @@
 
 - (id)initWithRenderWidgetHostViewMac:(RenderWidgetHostViewMac*)r {
   self = [super initWithFrame:NSZeroRect];
   if (self) {
     self.acceptsTouchEvents = YES;
     editCommand_helper_.reset(new RenderWidgetHostViewMacEditCommandHelper);
     editCommand_helper_->AddEditingSelectorsToClass([self class]);
 
     renderWidgetHostView_.reset(r);
     canBeKeyView_ = YES;
-    opaque_ = YES;
+    opaque_ = NO;
     pinchHasReachedZoomThreshold_ = false;
     isStylusEnteringProximity_ = false;
 
     // OpenGL support:
     if ([self respondsToSelector:
         @selector(setWantsBestResolutionOpenGLSurface:)]) {
       [self setWantsBestResolutionOpenGLSurface:YES];
     }
     [[NSNotificationCenter defaultCenter]
         addObserver:self
@@ skipping 1736 matching lines @@
 
 // "-webkit-app-region: drag | no-drag" is implemented on Mac by excluding
 // regions that are not draggable. (See ControlRegionView in
 // native_app_window_cocoa.mm). This requires the render host view to be
 // draggable by default.
 - (BOOL)mouseDownCanMoveWindow {
   return YES;
 }
 
 @end