Move creation of content TabContentsViews to content so that we can hide these headers through DEPS…

content/browser/mock_content_browser_client.cc

Index: content/browser/mock_content_browser_client.cc
===================================================================
--- content/browser/mock_content_browser_client.cc	(revision 126521)
+++ content/browser/mock_content_browser_client.cc	(working copy)
@@ -26,11 +26,16 @@
   return NULL;
 }
 
-WebContentsView* MockContentBrowserClient::CreateWebContentsView(
+WebContentsView* MockContentBrowserClient::OverrideCreateWebContentsView(
     WebContents* web_contents) {
   return new TestWebContentsView;
 }
 
+WebContentsViewDelegate* MockContentBrowserClient::GetWebContentsViewDelegate(
+    content::WebContents* web_contents) {
+  return NULL;
+}
+
 void MockContentBrowserClient::RenderViewHostCreated(
     RenderViewHost* render_view_host) {
 }