Make ShaderTranslatorCache thread safe

gpu/command_buffer/service/gles2_cmd_decoder.cc

Index: gpu/command_buffer/service/gles2_cmd_decoder.cc
diff --git a/gpu/command_buffer/service/gles2_cmd_decoder.cc b/gpu/command_buffer/service/gles2_cmd_decoder.cc
index c3bdae5d5d94a78b9cfa80d8087581f367118ec0..abaaaba3bf1492c37c120c29d447af9166bd4107 100644
--- a/gpu/command_buffer/service/gles2_cmd_decoder.cc
+++ b/gpu/command_buffer/service/gles2_cmd_decoder.cc
@@ -580,12 +580,14 @@ class GLES2DecoderImpl : public GLES2Decoder,
   virtual const char* GetCommandName(unsigned int command_id) const OVERRIDE;
 
   // Overridden from GLES2Decoder.
-  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) OVERRIDE;
+  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) OVERRIDE;
   virtual void Destroy(bool have_context) OVERRIDE;
   virtual void SetSurface(
       const scoped_refptr<gfx::GLSurface>& surface) OVERRIDE;
@@ -1724,6 +1726,7 @@ class GLES2DecoderImpl : public GLES2Decoder,
   error::Error current_decoder_error_;
 
   bool use_shader_translator_;
+  scoped_refptr<ShaderTranslatorCache> shader_translator_cache_;
   scoped_refptr<ShaderTranslator> vertex_translator_;
   scoped_refptr<ShaderTranslator> fragment_translator_;
 
@@ -2285,6 +2288,7 @@ GLES2DecoderImpl::~GLES2DecoderImpl() {
 bool GLES2DecoderImpl::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,
@@ -2319,6 +2323,8 @@ bool GLES2DecoderImpl::Initialize(
   context_ = context;
   surface_ = surface;
 
+  shader_translator_cache_ = shader_translator_cache;
+
   ContextCreationAttribHelper attrib_parser;
   if (!attrib_parser.Parse(attribs))
     return false;
@@ -2750,8 +2756,7 @@ bool GLES2DecoderImpl::InitializeShaderTranslator() {
   if (workarounds().unroll_for_loop_with_sampler_array_index)
     driver_bug_workarounds |= SH_UNROLL_FOR_LOOP_WITH_SAMPLER_ARRAY_INDEX;
 
-  ShaderTranslatorCache* cache = ShaderTranslatorCache::GetInstance();
-  vertex_translator_ = cache->GetTranslator(
+  vertex_translator_ = shader_translator_cache_->GetTranslator(
       SH_VERTEX_SHADER, shader_spec, &resources,
       implementation_type,
       static_cast<ShCompileOptions>(driver_bug_workarounds));
@@ -2761,7 +2766,7 @@ bool GLES2DecoderImpl::InitializeShaderTranslator() {
     return false;
   }
 
-  fragment_translator_ = cache->GetTranslator(
+  fragment_translator_ = shader_translator_cache_->GetTranslator(
       SH_FRAGMENT_SHADER, shader_spec, &resources,
       implementation_type,
       static_cast<ShCompileOptions>(driver_bug_workarounds));