[UMA] Use proper C++ objects to serialize tracked_objects across process boundaries.

content/browser/renderer_host/render_process_host_impl.cc

Index: content/browser/renderer_host/render_process_host_impl.cc
diff --git a/content/browser/renderer_host/render_process_host_impl.cc b/content/browser/renderer_host/render_process_host_impl.cc
index b4bd350e67a618d23b63beea019bf97c34b67f1c..a037596166a44a2405300ef8f71a27c8f1426ab6 100644
--- a/content/browser/renderer_host/render_process_host_impl.cc
+++ b/content/browser/renderer_host/render_process_host_impl.cc
@@ -537,7 +537,7 @@ void RenderProcessHostImpl::CreateMessageFilters() {
       content::BrowserContext::GetQuotaManager(browser_context),
       content::GetContentClient()->browser()->CreateQuotaPermissionContext()));
   channel_->AddFilter(new content::GamepadBrowserMessageFilter(this));
-  channel_->AddFilter(new ProfilerMessageFilter());
+  channel_->AddFilter(new content::ProfilerMessageFilter());
 }
 
 int RenderProcessHostImpl::GetNextRoutingID() {