This CL adds client.toDataURL which gets the contents...

core/cross/image_utils.h

 /*
  * Copyright 2009, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
@@ skipping 41 matching lines @@
   UNKNOWN,
   TGA,
   JPEG,
   PNG,
   DDS,
 };
 
 unsigned int GetNumComponentsForFormat(Texture::Format format);
 
 inline bool CheckImageDimensions(unsigned int width, unsigned int height) {
-  return width > 0 && height > 0 &&
-      width <= kMaxImageDimension && height <= kMaxImageDimension;
+  return width <= kMaxImageDimension && height <= kMaxImageDimension;
 }
 
 // Gets the number of mip-maps required for a full chain starting at
 // width x height.
 inline unsigned int ComputeMipMapCount(
     unsigned int width, unsigned int height) {
   return 1 + base::bits::Log2Floor(std::max(width, height));
 }
 
 // Gets the smallest power-of-two value that is at least as high as
@@ skipping 171 matching lines @@
                              int src_bmp_width, int src_bmp_height,
                              int* dest_x, int* dest_y,
                              int* dest_width, int* dest_height,
                              int dest_bmp_width, int dest_bmp_height);
 
 }  // namespace image
 }  // namespace o3d
 
 #endif  // O3D_CORE_CROSS_IMAGE_UTILS_H_