aw: Fix FBO restore in webview functor

android_webview/browser/render_thread_manager.cc

 // Copyright 2014 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 "android_webview/browser/render_thread_manager.h"
 
 #include <utility>
 
 #include "android_webview/browser/child_frame.h"
 #include "android_webview/browser/compositor_frame_producer.h"
@@ skipping 268 matching lines @@
     base::AutoLock lock(lock_);
     if (renderer_manager_key_ != manager->NullKey()) {
       manager->DidDrawGL(renderer_manager_key_);
     }
   }
 
   ScopedAppGLStateRestore state_restore(
       draw_info->mode == AwDrawGLInfo::kModeDraw
           ? ScopedAppGLStateRestore::MODE_DRAW
           : ScopedAppGLStateRestore::MODE_RESOURCE_MANAGEMENT);
-  // Set the correct FBO before kModeDraw. The GL commands run in kModeDraw
-  // require a correctly bound FBO. The FBO remains until the next kModeDraw.
-  // So kModeProcess between kModeDraws has correctly bound FBO, too.
-  if (hardware_renderer_) {
-    hardware_renderer_->SetBackingFrameBufferObject(
-        state_restore.framebuffer_binding_ext());
-  }
-
   ScopedAllowGL allow_gl;
   if (!hardware_renderer_ && draw_info->mode == AwDrawGLInfo::kModeDraw &&
       !IsInsideHardwareRelease() && HasFrameForHardwareRendererOnRT()) {
     hardware_renderer_.reset(new HardwareRenderer(this));
-    hardware_renderer_->SetBackingFrameBufferObject(
-        state_restore.framebuffer_binding_ext());
     hardware_renderer_->CommitFrame();
   }
 
   if (draw_info->mode == AwDrawGLInfo::kModeProcessNoContext) {
     LOG(ERROR) << "Received unexpected kModeProcessNoContext";
   }
 
   if (IsInsideHardwareRelease()) {
     hardware_renderer_has_frame_ = false;
     hardware_renderer_.reset();
@@ skipping 26 matching lines @@
     // The functor has only been attached to the view hierarchy if a compositor
     // frame has been generated. Thus, it should only be detached in this case.
     client_->DetachFunctorFromView();
 
     bool draw_functor_succeeded = client_->RequestInvokeGL(true);
     if (!draw_functor_succeeded) {
       LOG(ERROR) << "Unable to free GL resources. Has the Window leaked?";
       // Calling release on wrong thread intentionally.
       AwDrawGLInfo info;
       info.mode = AwDrawGLInfo::kModeProcess;
       DrawGL(&info);

[Tobias Sargeant, 2016/09/26 09:46:18]

Could this cause DCHECKs now, given that we could potentially create a
ScopedAppGLStateResore on the UI thread while the render thread object was in
scope?

[boliu, 2016/09/26 15:54:52]

Probably fine.. This is not supposed to happen in practice so failing DCHECKs is
ok. But it may crash without DCHECKs. If that's a problem in practice, we can
use a threadlocal I guess.

     }
   }
 
   GLViewRendererManager* manager = GLViewRendererManager::GetInstance();
 
   {
     base::AutoLock lock(lock_);
     if (renderer_manager_key_ != manager->NullKey()) {
       manager->Remove(renderer_manager_key_);
       renderer_manager_key_ = manager->NullKey();
@@ skipping 39 matching lines @@
     : render_thread_manager_(render_thread_manager) {
   DCHECK(!render_thread_manager_->IsInsideHardwareRelease());
   render_thread_manager_->SetInsideHardwareRelease(true);
 }
 
 RenderThreadManager::InsideHardwareReleaseReset::~InsideHardwareReleaseReset() {
   render_thread_manager_->SetInsideHardwareRelease(false);
 }
 
 }  // namespace android_webview