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