Move RenderViewHostObserver to content/public/browser/ and put it into the content namespace.

content/public/browser/render_view_host_observer.cc

Index: content/public/browser/render_view_host_observer.cc
diff --git a/content/browser/renderer_host/render_view_host_observer.cc b/content/public/browser/render_view_host_observer.cc
similarity index 92%
rename from content/browser/renderer_host/render_view_host_observer.cc
rename to content/public/browser/render_view_host_observer.cc
index d0fe61e8cbea1804d6c68b264711bdad015964c4..720d0046b4e494e2be54cd8cc4780f0ea8fe8d77 100644
--- a/content/browser/renderer_host/render_view_host_observer.cc
+++ b/content/public/browser/render_view_host_observer.cc
@@ -2,10 +2,12 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "content/browser/renderer_host/render_view_host_observer.h"
+#include "content/public/browser/render_view_host_observer.h"
 
 #include "content/browser/renderer_host/render_view_host.h"
 
+namespace content {
+
 RenderViewHostObserver::RenderViewHostObserver(RenderViewHost* render_view_host)
     : render_view_host_(render_view_host),
       routing_id_(render_view_host->routing_id()) {
@@ -46,3 +48,5 @@ void RenderViewHostObserver::RenderViewHostDestruction() {
   render_view_host_ = NULL;
   RenderViewHostDestroyed(rvh);
 }
+
+}  // namespace content