Move Render(View|Widget)Host and associated classes to content namespace.

content/browser/tab_contents/web_contents_view_mac.mm

Index: content/browser/tab_contents/web_contents_view_mac.mm
diff --git a/content/browser/tab_contents/web_contents_view_mac.mm b/content/browser/tab_contents/web_contents_view_mac.mm
index c3832a09b76c2a4b67fb9c6a71b4f4aebb603543..b718718dbe312cd04ffddf5bc5b060c861774143 100644
--- a/content/browser/tab_contents/web_contents_view_mac.mm
+++ b/content/browser/tab_contents/web_contents_view_mac.mm
@@ -91,7 +91,7 @@ void WebContentsViewMac::CreateView(const gfx::Size& initial_size) {
 }
 
 RenderWidgetHostView* WebContentsViewMac::CreateViewForWidget(
-    RenderWidgetHost* render_widget_host) {
+    content::RenderWidgetHost* render_widget_host) {
   if (render_widget_host->GetView()) {
     // During testing, the view will already be set up in most cases to the
     // test view, so we don't want to clobber it with a real one. To verify that
@@ -186,7 +186,7 @@ void WebContentsViewMac::StartDragging(
                               offset:offset];
 }
 
-void WebContentsViewMac::RenderViewCreated(RenderViewHost* host) {
+void WebContentsViewMac::RenderViewCreated(content::RenderViewHost* host) {
   // We want updates whenever the intrinsic width of the webpage changes.
   // Put the RenderView into that mode. The preferred width is used for example
   // when the "zoom" button in the browser window is clicked.