Connect up --disable-gl-multisampling to command buffer

chrome/gpu/gpu_channel.cc

Index: chrome/gpu/gpu_channel.cc
diff --git a/chrome/gpu/gpu_channel.cc b/chrome/gpu/gpu_channel.cc
index ec8dec250d43a414e566b7a4b8dcda3b37ba3a4f..7c81241ac159a06c50e041d1ff8fd55059b49184 100644
--- a/chrome/gpu/gpu_channel.cc
+++ b/chrome/gpu/gpu_channel.cc
@@ -32,6 +32,8 @@ GpuChannel::GpuChannel(GpuThread* gpu_thread,
   DCHECK(renderer_id);
   const CommandLine* command_line = CommandLine::ForCurrentProcess();
   log_messages_ = command_line->HasSwitch(switches::kLogPluginMessages);
+  disallowed_extensions_.multisampling =
+      command_line->HasSwitch(switches::kDisableGLMultisampling);
 }
 
 GpuChannel::~GpuChannel() {
@@ -95,7 +97,8 @@ void GpuChannel::CreateViewCommandBuffer(
 #if defined(ENABLE_GPU)
   *route_id = GenerateRouteID();
   scoped_ptr<GpuCommandBufferStub> stub(new GpuCommandBufferStub(
-      this, window, NULL, gfx::Size(), init_params.allowed_extensions,
+      this, window, NULL, gfx::Size(), disallowed_extensions_,
+      init_params.allowed_extensions,
       init_params.attribs, 0, *route_id, renderer_id_, render_view_id));
   router_.AddRoute(*route_id, stub.get());
   stubs_.AddWithID(stub.release(), *route_id);
@@ -174,6 +177,7 @@ void GpuChannel::OnCreateOffscreenCommandBuffer(
       gfx::kNullPluginWindow,
       parent_stub,
       size,
+      disallowed_extensions_,
       init_params.allowed_extensions,
       init_params.attribs,
       parent_texture_id,