Detach the output surface if bind fails.

cc/output/output_surface.cc

 // Copyright (c) 2013 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 "cc/output/output_surface.h"
 
 #include <stdint.h>
 
 #include "base/bind.h"
 #include "base/location.h"
@@ skipping 196 matching lines @@
 
   if (context_provider_.get()) {
     success = context_provider_->BindToCurrentThread();
     if (success) {
       context_provider_->SetLostContextCallback(base::Bind(
           &OutputSurface::DidLoseOutputSurface, base::Unretained(this)));
     }
   }
 
   if (!success)
-    client_ = NULL;
+    DetachFromClient();

[piman, 2016/05/06 19:41:40]

this will do the MemoryDumpManager::GetInstance()->UnregisterDumpProvider thing
- before the Register below.

Should we either:
1- do this after the register (i.e. in case of failure we register and
unregister immediately)
2- only register & unregister in case of success?

[danakj, 2016/05/06 20:19:56]

Argh OutputSurface. There are a lot of bad options here.

We can rely on the sub classes calling the base class BindToClient first and
early outting if it failed. Then we don't need to call the virtual
DetachFromClient and we could just clean up ourselves.

Or we can avoid that dependency, but then we need to register just to
unregister, as you say. Or store some extra state on this class to know that we
didn't fully finish BindToClient.

 
   // In certain cases, ThreadTaskRunnerHandle isn't set (Android Webview).
   // Don't register a dump provider in these cases.
   // TODO(ericrk): Get this working in Android Webview. crbug.com/517156
   if (client_ && base::ThreadTaskRunnerHandle::IsSet()) {
     // Now that we are on the context thread, register a dump provider with this
     // thread's task runner. This will overwrite any previous dump provider
     // registered.
     base::trace_event::MemoryDumpManager::GetInstance()->RegisterDumpProvider(
         this, "OutputSurface", base::ThreadTaskRunnerHandle::Get());
@@ skipping 133 matching lines @@
   if (context_provider_.get()) {
     context_provider_->SetLostContextCallback(
         ContextProvider::LostContextCallback());
   }
   context_provider_ = nullptr;
   client_ = nullptr;
   weak_ptr_factory_.InvalidateWeakPtrs();
 }
 
 }  // namespace cc