Android: Don't destroy LayerTreeHost when Surface goes away

ui/android/resources/ui_resource_provider.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 "ui/android/resources/ui_resource_provider.h"
-
-#include "cc/resources/ui_resource_client.h"
-#include "cc/trees/layer_tree_host.h"
-#include "ui/android/resources/ui_resource_client_android.h"
-
-namespace ui {
-
-UIResourceProvider::UIResourceProvider()
-    : host_(NULL), supports_etc1_npot_(false) {
-}
-
-UIResourceProvider::~UIResourceProvider() {
-  SetLayerTreeHost(NULL);
-}
-
-void UIResourceProvider::SetLayerTreeHost(cc::LayerTreeHost* host) {
-  if (host_ == host)
-    return;
-  host_ = host;
-  UIResourcesAreInvalid();
-}
-
-void UIResourceProvider::UIResourcesAreInvalid() {
-  UIResourceClientMap client_map;
-  client_map.swap(ui_resource_client_map_);
-  for (UIResourceClientMap::iterator iter = client_map.begin();
-       iter != client_map.end(); iter++) {
-    iter->second->UIResourceIsInvalid();
-  }
-}
-
-cc::UIResourceId UIResourceProvider::CreateUIResource(
-    ui::UIResourceClientAndroid* client) {
-  if (!host_)
-    return 0;
-  cc::UIResourceId id = host_->CreateUIResource(client);
-  DCHECK(ui_resource_client_map_.find(id) == ui_resource_client_map_.end());
-
-  ui_resource_client_map_[id] = client;
-  return id;
-}
-
-void UIResourceProvider::DeleteUIResource(cc::UIResourceId ui_resource_id) {
-  UIResourceClientMap::iterator iter =
-      ui_resource_client_map_.find(ui_resource_id);
-  DCHECK(iter != ui_resource_client_map_.end());
-
-  ui_resource_client_map_.erase(iter);
-
-  if (!host_)
-    return;
-  host_->DeleteUIResource(ui_resource_id);
-}
-
-bool UIResourceProvider::SupportsETC1NonPowerOfTwo() const {
-  return supports_etc1_npot_;
-}
-
-}  // namespace ui