During image destroy, delete textures only if we have a GL context.

gpu/command_buffer/service/image_manager.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.
 
 #include "gpu/command_buffer/service/image_manager.h"
 
 #include "ui/gl/gl_image.h"
 
 namespace gpu {
 namespace gles2 {
 
 ImageManager::ImageManager() {
 }
 
 ImageManager::~ImageManager() {
 }
 
+void ImageManager::Destroy(bool have_context) {
+  for (GLImageMap::const_iterator iter = images_.begin(); iter != images_.end();
+       ++iter)
+    iter->second.get()->Destroy(have_context);
+  images_.clear();
+}
+
 void ImageManager::AddImage(gfx::GLImage* image, int32 service_id) {
   images_[service_id] = image;
 }
 
 void ImageManager::RemoveImage(int32 service_id) {
   images_.erase(service_id);

[reveman, 2014/07/21 15:12:24]

when is GLImage::Destroy called for an image that is removed using a call to
RemoveImage?

[sohanjg, 2014/07/21 15:39:51]

hmm..GLImage::Destroy, will be invoked when cmd buffer and cmd decoder is
destroyed, cmd decoder will destroy image manager, holding all gl images.

[reveman, 2014/07/21 15:59:10]

It's not going to destroy this image as you're removing it right here. I'm not
sure calling Destroy here will work unless we make more changes. Here's the
sequence of events that I'm worried about:

1. Renderer1 register GpuMemoryBuffer and creates GLImage
2. Renderer1 binds GLImage to texture
3. Renderer1 shares texture with Renderer2
4. Renderer1 unregister GLImage (::Destroy is called)
5. Renderer2 tries to use texture and GPU process crashes as we're trying to use
a GLImage that has been destroyed

This would be incorrect usage by Renderer1 but it can't cause the GPU process to
crash. I think we need to make sure we handle these cases correctly and never
crash.

 }
 
 gfx::GLImage* ImageManager::LookupImage(int32 service_id) {
   GLImageMap::const_iterator iter = images_.find(service_id);
   if (iter != images_.end())
     return iter->second.get();
 
   return NULL;
 }
 
 }  // namespace gles2
 }  // namespace gpu