Expose a way to set a view's base background color.

Source/web/WebFrameImpl.cpp

 /*
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 2194 matching lines @@
 {
     TRACE_EVENT0("webkit", "WebFrameImpl::createFrameView");
 
     ASSERT(frame()); // If frame() doesn't exist, we probably didn't init properly.
 
     WebViewImpl* webView = viewImpl();
     bool isMainFrame = webView->mainFrameImpl()->frame() == frame();
     if (isMainFrame)
         webView->suppressInvalidations(true);
 
-    frame()->createView(webView->size(), Color::white, webView->isTransparent(), webView->fixedLayoutSize(), isMainFrame ? webView->isFixedLayoutModeEnabled() : 0);
+    frame()->createView(webView->size(), webView->baseBackgroundColor(), webView->isTransparent(), webView->fixedLayoutSize(), isMainFrame ? webView->isFixedLayoutModeEnabled() : 0);
     if (webView->shouldAutoResize() && isMainFrame)
         frame()->view()->enableAutoSizeMode(true, webView->minAutoSize(), webView->maxAutoSize());
 
     if (isMainFrame)
         webView->suppressInvalidations(false);
 
     if (isMainFrame && webView->devToolsAgentPrivate())
         webView->devToolsAgentPrivate()->mainFrameViewCreated(this);
 }
 
@@ skipping 256 matching lines @@
 
         // There is a possibility that the frame being detached was the only
         // pending one. We need to make sure final replies can be sent.
         flushCurrentScopingEffort(m_findRequestIdentifier);
 
         cancelPendingScopingEffort();
     }
 }
 
 } // namespace WebKit