Only allow webrtc HW offload for H264 encode for extension process.

extensions/renderer/dispatcher.cc

Index: extensions/renderer/dispatcher.cc
diff --git a/extensions/renderer/dispatcher.cc b/extensions/renderer/dispatcher.cc
index f09d5fdcdb705718825f7c2ea286cc177f6df965..6fa9fd6ed4c90ee20a1944de3d29f47a852293d9 100644
--- a/extensions/renderer/dispatcher.cc
+++ b/extensions/renderer/dispatcher.cc
@@ -183,7 +183,7 @@ Dispatcher::Dispatcher(DispatcherDelegate* delegate)
       v8_schema_registry_(new V8SchemaRegistry),
       is_webkit_initialized_(false),
       user_script_set_manager_observer_(this) {
-  const CommandLine& command_line = *(CommandLine::ForCurrentProcess());
+  CommandLine& command_line = *(CommandLine::ForCurrentProcess());
   is_extension_process_ =
       command_line.HasSwitch(extensions::switches::kExtensionProcess) ||
       command_line.HasSwitch(::switches::kSingleProcess);
@@ -191,6 +191,7 @@ Dispatcher::Dispatcher(DispatcherDelegate* delegate)
   if (is_extension_process_) {
     RenderThread::Get()->SetIdleNotificationDelayInMs(
         kInitialExtensionIdleHandlerDelayMs);
+    command_line.AppendSwitch(::switches::kEnableWebRtcHWH264Encoding);

[not at google - send to devlin, 2014/08/19 17:45:57]

It's not clear that appending the command line switch here would work. What if
the Dispatcher gets created after some other component which attempts to read
the switch?

There's code somewhere in the browser which sets command line switches for the
extension process. You should add it there.

[hshi1, 2014/08/19 18:07:39]

Agreed, I'l move the AppendSwitch to browser.

   }
 
   RenderThread::Get()->RegisterExtension(SafeBuiltins::CreateV8Extension());