Make ShaderTranslatorCache thread safe

gpu/command_buffer/service/gles2_cmd_decoder.h

Index: gpu/command_buffer/service/gles2_cmd_decoder.h
diff --git a/gpu/command_buffer/service/gles2_cmd_decoder.h b/gpu/command_buffer/service/gles2_cmd_decoder.h
index 03a4b546f09cf853170588777681b4f74dc7a884..7d021008f3f9cc016fe48503d2703c066181ffc9 100644
--- a/gpu/command_buffer/service/gles2_cmd_decoder.h
+++ b/gpu/command_buffer/service/gles2_cmd_decoder.h
@@ -16,6 +16,7 @@
 #include "gpu/command_buffer/common/capabilities.h"
 #include "gpu/command_buffer/service/common_decoder.h"
 #include "gpu/command_buffer/service/logger.h"
+#include "gpu/command_buffer/service/shader_translator_cache.h"
 #include "ui/gfx/size.h"
 #include "ui/gl/gl_context.h"
 
@@ -96,18 +97,22 @@ class GPU_EXPORT GLES2Decoder : public base::SupportsWeakPtr<GLES2Decoder>,
   // Parameters:
   //  surface: the GL surface to render to.
   //  context: the GL context to render to.
+  //  shader_translator_cache: the translator cache to get retrieve shader
+  //      translators.
   //  offscreen: whether to make the context offscreen or not. When FBO 0 is
   //      bound, offscreen contexts render to an internal buffer, onscreen ones
   //      to the surface.
   //  size: the size if the GL context is offscreen.
   // Returns:
   //   true if successful.
-  virtual bool Initialize(const scoped_refptr<gfx::GLSurface>& surface,
-                          const scoped_refptr<gfx::GLContext>& context,
-                          bool offscreen,
-                          const gfx::Size& size,
-                          const DisallowedFeatures& disallowed_features,
-                          const std::vector<int32>& attribs) = 0;
+  virtual bool Initialize(
+      const scoped_refptr<gfx::GLSurface>& surface,
+      const scoped_refptr<gfx::GLContext>& context,
+      const scoped_refptr<ShaderTranslatorCache>& shader_translator_cache,
+      bool offscreen,
+      const gfx::Size& size,
+      const DisallowedFeatures& disallowed_features,
+      const std::vector<int32>& attribs) = 0;
 
   // Destroys the graphics context.
   virtual void Destroy(bool have_context) = 0;