gpu: Mailbox emulation with EGLImage

ui/gl/gl_image.h

Index: ui/gl/gl_image.h
diff --git a/ui/gl/gl_image.h b/ui/gl/gl_image.h
index 08d2be60a5adfe51d5b9a4ff0144498fce6d66f9..ae4846fe9239de626c064c36ba569aea3c29a6ee 100644
--- a/ui/gl/gl_image.h
+++ b/ui/gl/gl_image.h
@@ -39,6 +39,12 @@ class GL_EXPORT GLImage : public base::RefCounted<GLImage> {
   // Called after the texture has been used for drawing.
   virtual void DidUseTexImage();
 
+  // Called before the image data will be modified.
+  virtual void WillModifyPixels() {}

[reveman, 2014/03/12 19:18:04]

This assumes that GLImage is not buffered like GLImageGLX or GLImageShm. I think
this should be called WillModifyTexImage as it's not the underlaying image data
that is necessarily modified.

Actually, I think I'd prefer Read/Write instead of Use/Modify. Wdyt?

nit: move implementation to gl_image.cc for consistency.

+
+  // Called after the image data has been modified.
+  virtual void DidModifyPixels() {}
+
   // Indicate that image should be released after use.
   // (For an Android work-around only).
   virtual void SetReleaseAfterUse();

[reveman, 2014/03/12 19:18:04]

Please change this too if you rename WillUseTexImage to WillReadTexImage.