Handle glTex{Sub}Image* calls with height==0.

gpu/command_buffer/client/gles2_implementation.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // A class to emulate GLES2 over command buffers.
 
 #include "gpu/command_buffer/client/gles2_implementation.h"
 
 #include <GLES2/gl2.h>
 #include <GLES2/gl2ext.h>
@@ skipping 2256 matching lines @@
 }
 
 namespace {
 
 void CopyRectToBuffer(const void* pixels,
                       uint32_t height,
                       uint32_t unpadded_row_size,
                       uint32_t pixels_padded_row_size,
                       void* buffer,
                       uint32_t buffer_padded_row_size) {
+  if (height == 0)
+    return;
   const int8_t* source = static_cast<const int8_t*>(pixels);
   int8_t* dest = static_cast<int8_t*>(buffer);
   if (pixels_padded_row_size != buffer_padded_row_size) {
     // the last row is copied unpadded at the end
     for (; height > 1; --height) {
       memcpy(dest, source, buffer_padded_row_size);
       dest += buffer_padded_row_size;
       source += pixels_padded_row_size;
     }
     memcpy(dest, source, unpadded_row_size);
@@ skipping 4260 matching lines @@
   CheckGLError();
 }
 
 // Include the auto-generated part of this file. We split this because it means
 // we can easily edit the non-auto generated parts right here in this file
 // instead of having to edit some template or the code generator.
 #include "gpu/command_buffer/client/gles2_implementation_impl_autogen.h"
 
 }  // namespace gles2
 }  // namespace gpu