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

gpu/command_buffer/client/gles2_implementation.cc

Index: gpu/command_buffer/client/gles2_implementation.cc
diff --git a/gpu/command_buffer/client/gles2_implementation.cc b/gpu/command_buffer/client/gles2_implementation.cc
index 6d6e1a54602698e36890b72aa5f043cda7cea0ae..5033e945292348e897ed3b38c7b469fb64faa0dd 100644
--- a/gpu/command_buffer/client/gles2_implementation.cc
+++ b/gpu/command_buffer/client/gles2_implementation.cc
@@ -2274,6 +2274,8 @@ void CopyRectToBuffer(const void* pixels,
                       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) {