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

content/browser/renderer_host/render_view_host_impl.cc

Index: content/browser/renderer_host/render_view_host_impl.cc
diff --git a/content/browser/renderer_host/render_view_host_impl.cc b/content/browser/renderer_host/render_view_host_impl.cc
index 2c5b0248ac0ca691f5a1fdab1fb590a6eb4604d1..5ea15717ef69497567b525e5517ad3dd33e88d04 100644
--- a/content/browser/renderer_host/render_view_host_impl.cc
+++ b/content/browser/renderer_host/render_view_host_impl.cc
@@ -67,6 +67,7 @@ using content::BrowserThread;
 using content::DomOperationNotificationDetails;
 using content::DOMStorageContext;
 using content::HostZoomMap;
+using content::RenderWidgetHost;
 using content::RenderViewHostDelegate;
 using content::SessionStorageNamespace;
 using content::SiteInstance;
@@ -100,6 +101,8 @@ base::i18n::TextDirection WebTextDirectionToChromeTextDirection(
 
 }  // namespace
 
+namespace content {
+
 ///////////////////////////////////////////////////////////////////////////////
 // RenderViewHost, public:
 
@@ -1669,3 +1672,5 @@ void RenderViewHostImpl::SetSwappedOut(bool is_swapped_out) {
 void RenderViewHostImpl::ClearPowerSaveBlockers() {
   STLDeleteValues(&power_save_blockers_);
 }
+
+}  // namespace content