Enhance chrome.app.window API with window background color

extensions/components/native_app_window/native_app_window_views.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 "extensions/components/native_app_window/native_app_window_views.h"
 
 #include "base/threading/sequenced_worker_pool.h"
 #include "content/public/browser/render_view_host.h"
 #include "content/public/browser/render_widget_host.h"
 #include "content/public/browser/render_widget_host_view.h"
@@ skipping 273 matching lines @@
                                                      bool active) {
   app_window_->OnNativeWindowChanged();
   if (active)
     app_window_->OnNativeWindowActivated();
 }
 
 // WebContentsObserver implementation.
 
 void NativeAppWindowViews::RenderViewCreated(
     content::RenderViewHost* render_view_host) {
+  content::RenderWidgetHostView* view =
+      render_view_host->GetWidget()->GetView();
+  DCHECK(view);
+
   if (app_window_->requested_alpha_enabled() && CanHaveAlphaEnabled()) {
-    content::RenderWidgetHostView* view =
-        render_view_host->GetWidget()->GetView();
-    DCHECK(view);
     view->SetBackgroundColor(SK_ColorTRANSPARENT);

[Reilly Grant (use Gerrit), 2017/03/10 18:39:18]

This implies that background color and alpha are mutually exclusive. This should
be documented in the IDL.

+  } else if (app_window_->backgroundColor() != SK_ColorWHITE) {
+    view->SetBackgroundColor(app_window_->backgroundColor());
   }
 }
 
 void NativeAppWindowViews::RenderViewHostChanged(
     content::RenderViewHost* old_host,
     content::RenderViewHost* new_host) {
   OnViewWasResized();
 }
 
 // views::View implementation.
@@ skipping 124 matching lines @@
 
 bool NativeAppWindowViews::CanHaveAlphaEnabled() const {
   return widget_->IsTranslucentWindowOpacitySupported();
 }
 
 void NativeAppWindowViews::SetVisibleOnAllWorkspaces(bool always_visible) {
   widget_->SetVisibleOnAllWorkspaces(always_visible);
 }
 
 }  // namespace native_app_window