Clear RenderThread of any Chrome specific code, and move a bunch of stuff out of RenderView.

content/common/view_messages.h

Index: content/common/view_messages.h
===================================================================
--- content/common/view_messages.h	(revision 81801)
+++ content/common/view_messages.h	(working copy)
@@ -1154,6 +1154,12 @@
                     int /* request_id */,
                     IPC::ChannelHandle /* handle */)
 
+// Tells the renderer to empty its plugin list cache, optional reloading
+// pages containing plugins.
+IPC_MESSAGE_CONTROL1(ViewMsg_PurgePluginListCache,
+                     bool /* reload_pages */)
+
+
 // Messages sent from the renderer to the browser.
 
 // Sent by the renderer when it is creating a new window.  The browser creates