Revert of Sets the default background color of inline signin and user manager to grey

content/browser/renderer_host/render_widget_host_view_mac.mm

Index: content/browser/renderer_host/render_widget_host_view_mac.mm
diff --git a/content/browser/renderer_host/render_widget_host_view_mac.mm b/content/browser/renderer_host/render_widget_host_view_mac.mm
index 77b7f03f39e4b763a70d087f3e64a3026cc7cb57..18a7d2fd03fa0708823cea6abbddd4adc4797315 100644
--- a/content/browser/renderer_host/render_widget_host_view_mac.mm
+++ b/content/browser/renderer_host/render_widget_host_view_mac.mm
@@ -58,7 +58,6 @@
 #include "content/public/browser/user_metrics.h"
 #include "content/public/browser/web_contents.h"
 #include "skia/ext/platform_canvas.h"
-#include "skia/ext/skia_utils_mac.h"
 #include "third_party/WebKit/public/platform/WebScreenInfo.h"
 #include "third_party/WebKit/public/web/WebInputEvent.h"
 #include "third_party/WebKit/public/web/mac/WebInputEventFactory.h"
@@ -538,11 +537,11 @@
   cocoa_view_ = [[[RenderWidgetHostViewCocoa alloc]
                   initWithRenderWidgetHostViewMac:this] autorelease];
 
-  // Paint this view host with |background_color_| when there is no content
-  // ready to draw.
+  // Make this view host a solid white layer when there is no content ready to
+  // draw.
   background_layer_.reset([[CALayer alloc] init]);
   [background_layer_
-      setBackgroundColor:gfx::CGColorCreateFromSkColor(background_color_)];
+      setBackgroundColor:CGColorGetConstantColor(kCGColorWhite)];
   [cocoa_view_ setLayer:background_layer_];
   [cocoa_view_ setWantsLayer:YES];
 
@@ -1529,15 +1528,10 @@
   helper.ShowDefinitionForSelection();
 }
 
-void RenderWidgetHostViewMac::SetBackgroundColor(SkColor color) {
-  RenderWidgetHostViewBase::SetBackgroundColor(color);
+void RenderWidgetHostViewMac::SetBackgroundOpaque(bool opaque) {
+  RenderWidgetHostViewBase::SetBackgroundOpaque(opaque);
   if (render_widget_host_)
-    render_widget_host_->SetBackgroundOpaque(GetBackgroundOpaque());
-
-  if (background_layer_) {
-    [background_layer_
-        setBackgroundColor:gfx::CGColorCreateFromSkColor(background_color_)];
-  }
+    render_widget_host_->SetBackgroundOpaque(opaque);
 }
 
 BrowserAccessibilityManager*