Use the NTP background color instead of white when there is no other info.

chrome/browser/ui/views/frame/contents_web_view.cc

 // Copyright 2014 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 "chrome/browser/ui/views/frame/contents_web_view.h"
 
 #include "chrome/browser/themes/theme_properties.h"
 #include "chrome/browser/ui/views/status_bubble_views.h"
+#include "content/public/browser/render_widget_host_view.h"
 #include "content/public/browser/web_contents.h"
 #include "ui/base/theme_provider.h"
 #include "ui/compositor/layer_tree_owner.h"
 #include "ui/views/background.h"
 
 #if defined(USE_AURA)
 #include "ui/aura/window.h"
 #include "ui/wm/core/window_util.h"
 #endif
 
@@ skipping 38 matching lines @@
   // view is sized specially for fullscreen tab capture.  See WebView header
   // file comments for more details.
   const int kBackgroundBrightness = 0x33;  // 20%
   const SkColor ntp_background =
       theme->GetColor(ThemeProperties::COLOR_NTP_BACKGROUND);
   set_background(views::Background::CreateSolidBackground(
       SkColorGetR(ntp_background) * kBackgroundBrightness / 0xFF,
       SkColorGetG(ntp_background) * kBackgroundBrightness / 0xFF,
       SkColorGetB(ntp_background) * kBackgroundBrightness / 0xFF,
       SkColorGetA(ntp_background)));
+
+  content::RenderWidgetHostView* rwhv = nullptr;
+  if (web_contents())
+    rwhv = web_contents()->GetRenderWidgetHostView();
+  if (rwhv)

[sky, 2016/05/02 20:04:33]

nit: move inside if block on 70 (or early return if web_contents() is null).

[chrishtr, 2016/05/02 20:24:02]

Done.

+    rwhv->SetBackgroundColor(ntp_background);
 }
 
 void ContentsWebView::OnLayerRecreated(ui::Layer* old_layer,
                                        ui::Layer* new_layer) {
   if (!cloned_layer_tree_)
     return;
 
   // Our layer has been recreated and we have a clone of the WebContents
   // layer. Combined this means we're about to be destroyed and an animation is
   // in effect. The animation cloned our layer, but it won't create another
@@ skipping 30 matching lines @@
   cloned_layer_tree_->root()->SetBounds(
       gfx::Rect(origin, cloned_layer_tree_->root()->bounds().size()));
   layer()->Add(cloned_layer_tree_->root());
 }
 
 void ContentsWebView::DestroyClonedLayer() {
   cloned_layer_tree_.reset();
   SetPaintToLayer(false);
   set_layer_owner_delegate(nullptr);
 }
+
+void ContentsWebView::RenderViewReady() {
+  // Apply the theme color to be the default background on startup.
+  OnThemeChanged();
+  WebView::RenderViewReady();
+}