Make ShaderTranslatorCache thread safe

content/common/gpu/gpu_channel_manager.h

Index: content/common/gpu/gpu_channel_manager.h
diff --git a/content/common/gpu/gpu_channel_manager.h b/content/common/gpu/gpu_channel_manager.h
index 638028eb0bf219a7c94d49659e1d784dbc86f2f1..8ea38c76cc9d3359e27b28b4ef642b329e71c265 100644
--- a/content/common/gpu/gpu_channel_manager.h
+++ b/content/common/gpu/gpu_channel_manager.h
@@ -34,6 +34,7 @@ namespace gpu {
 namespace gles2 {
 class MailboxManager;
 class ProgramCache;
+class ShaderTranslatorCache;
 }
 }
 
@@ -82,6 +83,7 @@ class GpuChannelManager : public IPC::Listener,
   void RemoveRoute(int32 routing_id);
 
   gpu::gles2::ProgramCache* program_cache();
+  gpu::gles2::ShaderTranslatorCache* shader_translator_cache();
 
   GpuMemoryManager* gpu_memory_manager() { return &gpu_memory_manager_; }
 
@@ -144,6 +146,7 @@ class GpuChannelManager : public IPC::Listener,
   GpuWatchdog* watchdog_;
   scoped_refptr<SyncPointManager> sync_point_manager_;
   scoped_ptr<gpu::gles2::ProgramCache> program_cache_;
+  scoped_refptr<gpu::gles2::ShaderTranslatorCache> shader_translator_cache_;
   scoped_refptr<gfx::GLSurface> default_offscreen_surface_;
   ImageOperationQueue image_operations_;