Mac: Push background color from RWHVMac to CALayer

Make RenderWidgetHostViewMac::SetBackgroundColor set the background
color of the widget.

Push the NTP background color to RWHVMac from TabContentsController.

BUG=470669

Review URL: https://codereview.chromium.org/1817373002

Cr-Commit-Position: refs/heads/master@{#382955}

2 files changed, 19 insertions, 0 deletions

diff --git a/chrome/browser/ui/cocoa/tab_contents/tab_contents_controller.mm b/chrome/browser/ui/cocoa/tab_contents/tab_contents_controller.mm
index 14b7dce..08c4324 100644
--- a/chrome/browser/ui/cocoa/tab_contents/tab_contents_controller.mm
+++ b/chrome/browser/ui/cocoa/tab_contents/tab_contents_controller.mm
@@ -246,6 +246,17 @@ class FullscreenObserver : public WebContentsObserver {
                                           NSViewHeightSizable];
 
   [contentsContainer setNeedsDisplay:YES];
+
+  // Push the background color down to the RenderWidgetHostView, so that if
+  // there is a flash between contents appearing, it will be the theme's color,
+  // not white.
+  SkColor skBackgroundColor = SK_ColorWHITE;
+  const ThemeProvider* theme = [[[self view] window] themeProvider];
+  if (theme)
+    skBackgroundColor = theme->GetColor(ThemeProperties::COLOR_NTP_BACKGROUND);
+  content::RenderWidgetHostView* rwhv = contents_->GetRenderWidgetHostView();
+  if (rwhv)
+    rwhv->SetBackgroundColor(skBackgroundColor);
 }
 
 - (void)updateFullscreenWidgetFrame {
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 3a99741..0b6ad26 100644
--- a/content/browser/renderer_host/render_widget_host_view_mac.mm
+++ b/content/browser/renderer_host/render_widget_host_view_mac.mm
@@ -1682,6 +1682,9 @@ void RenderWidgetHostViewMac::ShowDefinitionForSelection() {
 }
 
 void RenderWidgetHostViewMac::SetBackgroundColor(SkColor color) {
+  if (color == background_color_)
+    return;
+
   RenderWidgetHostViewBase::SetBackgroundColor(color);
   bool opaque = GetBackgroundOpaque();
 
@@ -1691,6 +1694,11 @@ void RenderWidgetHostViewMac::SetBackgroundColor(SkColor color) {
   [cocoa_view_ setOpaque:opaque];
   if (browser_compositor_state_ != BrowserCompositorDestroyed)
     browser_compositor_->compositor()->SetHostHasTransparentBackground(!opaque);
+
+  ScopedCAActionDisabler disabler;
+  base::ScopedCFTypeRef<CGColorRef> cg_color(
+      skia::CGColorCreateFromSkColor(color));
+  [background_layer_ setBackgroundColor:cg_color];
 }
 
 BrowserAccessibilityManager*