Introduce content::RenderWidgetHostViewPort (in content/port/browser).

content/browser/renderer_host/test_render_view_host.cc

Index: content/browser/renderer_host/test_render_view_host.cc
diff --git a/content/browser/renderer_host/test_render_view_host.cc b/content/browser/renderer_host/test_render_view_host.cc
index 7cabedfbacc3109330903542fba3e6885c4cd1fb..8a529edfa7dcf738ef7ef178156a4b7de6002347 100644
--- a/content/browser/renderer_host/test_render_view_host.cc
+++ b/content/browser/renderer_host/test_render_view_host.cc
@@ -79,7 +79,7 @@ TestRenderViewHost::TestRenderViewHost(SiteInstance* instance,
   // For normal RenderViewHosts, this is freed when |Shutdown()| is called.
   // For TestRenderViewHost, the view is explicitly deleted in the destructor
   // below, because TestRenderWidgetHostView::Destroy() doesn't |delete this|.
-  SetView(new TestRenderWidgetHostView(this));
+  SetView(new content::TestRenderWidgetHostView(this));
 }
 
 TestRenderViewHost::~TestRenderViewHost() {
@@ -154,6 +154,8 @@ void TestRenderViewHost::set_contents_mime_type(const std::string& mime_type) {
   contents_mime_type_ = mime_type;
 }
 
+namespace content {
+
 TestRenderWidgetHostView::TestRenderWidgetHostView(RenderWidgetHost* rwh)
     : rwh_(rwh),
       is_showing_(false) {
@@ -306,6 +308,8 @@ bool TestRenderWidgetHostView::LockMouse() {
 void TestRenderWidgetHostView::UnlockMouse() {
 }
 
+}  // namespace content
+
 TestRenderViewHostFactory::TestRenderViewHostFactory(
     content::RenderProcessHostFactory* rph_factory)
     : render_process_host_factory_(rph_factory) {