Pull the Activity context from WindowAndroid if possible

ui/android/resources/resource_manager_impl.h

 // 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.
 
 #ifndef UI_ANDROID_RESOURCES_RESOURCE_MANAGER_IMPL_H_
 #define UI_ANDROID_RESOURCES_RESOURCE_MANAGER_IMPL_H_
 
 #include "base/id_map.h"
 #include "ui/android/resources/resource_manager.h"
 #include "ui/android/ui_android_export.h"
 #include "ui/gfx/geometry/rect.h"
+#include "ui/gfx/native_widget_types.h"
 
 namespace ui {
 
 class UI_ANDROID_EXPORT ResourceManagerImpl : public ResourceManager {
  public:
   static ResourceManagerImpl* FromJavaObject(jobject jobj);
 
-  ResourceManagerImpl();
+  explicit ResourceManagerImpl(gfx::NativeWindow native_window);
   ~ResourceManagerImpl() override;
 
   void Init(cc::LayerTreeHost* host);
 
   // ResourceManager implementation.
   base::android::ScopedJavaLocalRef<jobject> GetJavaObject() override;
   Resource* GetResource(AndroidResourceType res_type, int res_id) override;
   void PreloadResource(AndroidResourceType res_type, int res_id) override;
   CrushedSpriteResource* GetCrushedSpriteResource(
       int bitmap_res_id, int metadata_res_id) override;
@@ skipping 54 matching lines @@
   CrushedSpriteResourceMap crushed_sprite_resources_;
 
   base::android::ScopedJavaGlobalRef<jobject> java_obj_;
 
   DISALLOW_COPY_AND_ASSIGN(ResourceManagerImpl);
 };
 
 }  // namespace ui
 
 #endif  // UI_ANDROID_RESOURCES_RESOURCE_MANAGER_IMPL_H_