Implement client side PBOs for glReadPixel

content/common/gpu/client/gl_helper.h

Index: content/common/gpu/client/gl_helper.h
diff --git a/content/common/gpu/client/gl_helper.h b/content/common/gpu/client/gl_helper.h
index 40e25ebe716b955c99507f0e373fa02d24ea7a61..aa0b61b4030b1e99139ecae1484568d02e63822f 100644
--- a/content/common/gpu/client/gl_helper.h
+++ b/content/common/gpu/client/gl_helper.h
@@ -24,8 +24,7 @@ namespace content {
 // interfaces.
 class GLHelper {
  public:
-  GLHelper(WebKit::WebGraphicsContext3D* context,
-           WebKit::WebGraphicsContext3D* context_for_thread);
+  GLHelper(WebKit::WebGraphicsContext3D* context);
   virtual ~GLHelper();
 
   WebKit::WebGraphicsContext3D* context() const;
@@ -82,12 +81,8 @@ class GLHelper {
   void InitCopyTextToImpl();
 
   WebKit::WebGraphicsContext3D* context_;
-  WebKit::WebGraphicsContext3D* context_for_thread_;
   scoped_ptr<CopyTextureToImpl> copy_texture_to_impl_;
 
-  // The number of all GLHelper instances.
-  static base::subtle::Atomic32 count_;
-
   DISALLOW_COPY_AND_ASSIGN(GLHelper);
 };