Add mouse input forwarding to gpu service

gpu/command_buffer/service/gpu_switches.cc

Index: gpu/command_buffer/service/gpu_switches.cc
diff --git a/gpu/command_buffer/service/gpu_switches.cc b/gpu/command_buffer/service/gpu_switches.cc
index 8f5bc35cf407344b282aeb778e73be2b48357272..00722564e7f7efca38b97eaacf497fef2c157e56 100644
--- a/gpu/command_buffer/service/gpu_switches.cc
+++ b/gpu/command_buffer/service/gpu_switches.cc
@@ -56,6 +56,10 @@ const char kDisableGpuShaderDiskCache[]     = "disable-gpu-shader-disk-cache";
 const char kEnableShareGroupAsyncTextureUpload[] =
     "enable-share-group-async-texture-upload";
 
+// Enable WebGL subscribe uniform extension.
+const char kEnableSubscribeUniformExtension[] =
+    "enable-subscribe-uniform-extension";
+
 // Simulates shared textures when share groups are not available. Not available
 // everywhere.
 const char kEnableThreadedTextureMailboxes[] =
@@ -77,6 +81,7 @@ const char* kGpuSwitches[] = {
   kGpuProgramCacheSizeKb,
   kDisableGpuShaderDiskCache,
   kEnableShareGroupAsyncTextureUpload,
+  kEnableSubscribeUniformExtension,
 };
 
 const int kNumGpuSwitches = arraysize(kGpuSwitches);