added gpu_benchmarking_extension boilerplate and hooked it up to a new switch.

content/renderer/render_thread_impl.cc

Index: content/renderer/render_thread_impl.cc
diff --git a/content/renderer/render_thread_impl.cc b/content/renderer/render_thread_impl.cc
index 3f6756a1e183fd40a2b3a3c3cc1522d27985fa6b..a78edaba67d4678ff3e1f68232b18048dce68af3 100644
--- a/content/renderer/render_thread_impl.cc
+++ b/content/renderer/render_thread_impl.cc
@@ -53,6 +53,7 @@
 #include "content/renderer/dom_storage/webstoragearea_impl.h"
 #include "content/renderer/dom_storage/webstoragenamespace_impl.h"
 #include "content/renderer/gpu/compositor_thread.h"
+#include "content/renderer/gpu_benchmarking_extension.h"

[jam, 2012/06/08 00:52:04]

should this code be under content/renderer/gpu/?

[dmurph, 2012/06/08 18:36:22]

following the alphabetical order of 'renderer' (which is the only order that
makes sense here), 'gpu' comes before 'gpu_'.  

[jam, 2012/06/08 18:39:13]

I meant should the file itself be located in content/renderer/gpu/

[dmurph, 2012/06/08 19:30:13]

Ah.  Yes, it should.  Moved.

 #include "content/renderer/media/audio_input_message_filter.h"
 #include "content/renderer/media/audio_message_filter.h"
 #include "content/renderer/media/media_stream_center.h"
@@ -241,6 +242,10 @@ void RenderThreadImpl::Init() {
 
   content::GetContentClient()->renderer()->RenderThreadStarted();
 
+  CommandLine* command_line = CommandLine::ForCurrentProcess();
+  if (command_line->HasSwitch(switches::kEnableGpuBenchmarking))
+      RegisterExtension(content::GpuBenchmarkingExtension::Get());

[jam, 2012/06/08 00:52:04]

nit: 2 spaces

[dmurph, 2012/06/08 18:36:22]

Done.

+
   // Note that under Linux, the media library will normally already have
   // been initialized by the Zygote before this instance became a Renderer.
   FilePath media_path;