Fix Crash on destructor of OffscreenCanvasSurfaceImpl during ConnectionError

content/browser/renderer_host/offscreen_canvas_surface_impl.cc

 // Copyright 2016 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 "content/browser/renderer_host/offscreen_canvas_surface_impl.h"
 
 #include "base/bind_helpers.h"
 #include "cc/surfaces/surface.h"
 #include "cc/surfaces/surface_manager.h"
 #include "content/browser/compositor/surface_utils.h"
@@ skipping 10 matching lines @@
 
 OffscreenCanvasSurfaceImpl::OffscreenCanvasSurfaceImpl(
     mojo::InterfaceRequest<blink::mojom::OffscreenCanvasSurface> request)
     : id_allocator_(CreateSurfaceIdAllocator()),
       binding_(this, std::move(request)) {}
 
 OffscreenCanvasSurfaceImpl::~OffscreenCanvasSurfaceImpl() {
   if (!GetSurfaceManager()) {
     // Inform both members that SurfaceManager's no longer alive to
     // avoid their destruction errors.
-    surface_factory_->didDestroySurfaceManager();
-    id_allocator_->didDestroySurfaceManager();
+    if (surface_factory_)
+        surface_factory_->didDestroySurfaceManager();
+    if (id_allocator_)
+        id_allocator_->didDestroySurfaceManager();
   }
   surface_factory_->Destroy(surface_id_);
 }
 
 void OffscreenCanvasSurfaceImpl::GetSurfaceId(
     const GetSurfaceIdCallback& callback) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
 
   surface_id_ = id_allocator_->GenerateId();
 
@@ skipping 33 matching lines @@
     const cc::ReturnedResourceArray& resources) {}
 
 void OffscreenCanvasSurfaceImpl::WillDrawSurface(cc::SurfaceId id,
                                                  const gfx::Rect& damage_rect) {
 }
 
 void OffscreenCanvasSurfaceImpl::SetBeginFrameSource(
     cc::BeginFrameSource* begin_frame_source) {}
 
 }  // namespace content