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

content/common/gpu/gpu_command_buffer_stub.cc

Index: content/common/gpu/gpu_command_buffer_stub.cc
diff --git a/content/common/gpu/gpu_command_buffer_stub.cc b/content/common/gpu/gpu_command_buffer_stub.cc
index 189215122af0bff2aeb71e88d7364c1a7ad0fe21..f002bb105f2c0ba73d3cf2da534ab99b17114c3b 100644
--- a/content/common/gpu/gpu_command_buffer_stub.cc
+++ b/content/common/gpu/gpu_command_buffer_stub.cc
@@ -946,6 +946,10 @@ void GpuCommandBufferStub::OnRegisterGpuMemoryBuffer(
   if (decoder_) {
     gpu::gles2::ImageManager* image_manager = decoder_->GetImageManager();
     DCHECK(image_manager);
+    if (image_manager->LookupImage(id)) {
+      LOG(ERROR) << "Image already exists with same ID.";
+      return;
+    }
     image_manager->AddImage(image.get(), id);
   }
 }
@@ -956,6 +960,10 @@ void GpuCommandBufferStub::OnDestroyGpuMemoryBuffer(int32 id) {
   if (decoder_) {
     gpu::gles2::ImageManager* image_manager = decoder_->GetImageManager();
     DCHECK(image_manager);
+    if (!image_manager->LookupImage(id)) {
+      LOG(ERROR) << "Image with ID doesn't exist.";

[no sievers, 2014/07/28 17:38:25]

nit: maybe the checks here and above fit better inside ImageManager?
Then you could maybe avoid doing two lookups. I think hash_map::erase() returns
the number of elements erased.

[reveman, 2014/07/28 18:00:00]

I suggested we check this here and just DCHECK in the image manager as whether
it's OK to crash or not depends on the command buffer. I'm fine doing it the
other way though. AddImage just needs to be able to return false.

[sohanjg, 2014/07/30 10:30:26]

sievers@ should we take the checks back to imagemanager or you are ok at this
being here ?

+      return;
+    }
     image_manager->RemoveImage(id);
   }
 }