(not for commit) Simplified multi-threaded Ganesh with lock on Flush only.

cc/resources/resource_provider.h

Index: cc/resources/resource_provider.h
diff --git a/cc/resources/resource_provider.h b/cc/resources/resource_provider.h
index 1fb5b60a23596c5b42f6169698871756b96a96ac..25fd37b68e47337506a63d96517764c7f2f13820 100644
--- a/cc/resources/resource_provider.h
+++ b/cc/resources/resource_provider.h
@@ -86,6 +86,7 @@ class CC_EXPORT ResourceProvider {
       BlockingTaskRunner* blocking_main_thread_task_runner,
       int highp_threshold_min,
       bool use_rgba_4444_texture_format,
+      bool use_worker_context_for_gr,
       size_t id_allocation_chunk_size);
   virtual ~ResourceProvider();
 
@@ -332,13 +333,12 @@ class CC_EXPORT ResourceProvider {
   class CC_EXPORT ScopedWriteLockGr {
    public:
     ScopedWriteLockGr(ResourceProvider* resource_provider,
-                      ResourceProvider::ResourceId resource_id,
-                      bool use_distance_field_text,
-                      bool can_use_lcd_text,
-                      int msaa_sample_count);
+                      ResourceProvider::ResourceId resource_id);
     ~ScopedWriteLockGr();
 
-    SkSurface* get_sk_surface() { return sk_surface_.get(); }
+    SkSurface* GetSkSurface(bool use_distance_field_text,
+                            bool can_use_lcd_text,
+                            int msaa_sample_count);
 
    private:
     ResourceProvider* resource_provider_;
@@ -426,6 +426,8 @@ class CC_EXPORT ResourceProvider {
 
   static GLint GetActiveTextureUnit(gpu::gles2::GLES2Interface* gl);
 
+  OutputSurface* output_surface() { return output_surface_; }
+
  private:
   struct Resource {
     enum Origin { Internal, External, Delegated };
@@ -524,6 +526,7 @@ class CC_EXPORT ResourceProvider {
                    BlockingTaskRunner* blocking_main_thread_task_runner,
                    int highp_threshold_min,
                    bool use_rgba_4444_texture_format,
+                   bool use_worker_context_for_gr,
                    size_t id_allocation_chunk_size);
 
   void CleanUpGLIfNeeded();
@@ -587,6 +590,7 @@ class CC_EXPORT ResourceProvider {
 
   scoped_refptr<Fence> current_read_lock_fence_;
   bool use_rgba_4444_texture_format_;
+  bool use_worker_context_for_gr_;
 
   const size_t id_allocation_chunk_size_;
   scoped_ptr<IdAllocator> texture_id_allocator_;