arc: Revamp the ArcBridgeService interface

components/arc/ime/arc_ime_bridge_impl.h

 // 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.
 
 #ifndef COMPONENTS_ARC_IME_ARC_IME_BRIDGE_IMPL_H_
 #define COMPONENTS_ARC_IME_ARC_IME_BRIDGE_IMPL_H_
 
 #include "base/macros.h"
 #include "base/strings/string16.h"
 #include "components/arc/arc_bridge_service.h"
 #include "components/arc/common/ime.mojom.h"
 #include "components/arc/ime/arc_ime_bridge.h"
+#include "components/arc/instance_holder.h"
 #include "mojo/public/cpp/bindings/binding.h"
 #include "ui/base/ime/text_input_type.h"
 #include "ui/gfx/geometry/rect.h"
 
 namespace ui {
 struct CompositionText;
 }  // namespace ui
 
 namespace arc {
 
 // This class encapsulates the detail of IME related IPC between
 // Chromium and the ARC container.
 class ArcImeBridgeImpl : public ArcImeBridge,
                          public mojom::ImeHost,
-                         public ArcBridgeService::Observer {
+                         public InstanceHolder<mojom::ImeInstance>::Observer {
  public:
   ArcImeBridgeImpl(Delegate* delegate, ArcBridgeService* bridge_service);
   ~ArcImeBridgeImpl() override;
 
-  // arc::ArcBridgeService::Observer overrides:
-  void OnImeInstanceReady() override;
+  // arc::InstanceHolder<mojom::ImeInstance>::Observer overrides:
+  void OnInstanceReady() override;
 
   // ArcImeBridge overrides:
   void SendSetCompositionText(const ui::CompositionText& composition) override;
   void SendConfirmCompositionText() override;
   void SendInsertText(const base::string16& text) override;
   void SendOnKeyboardBoundsChanging(const gfx::Rect& new_bounds) override;
   void SendExtendSelectionAndDelete(size_t before, size_t after) override;
 
   // arc::mojom::ImeHost overrides:
   void OnTextInputTypeChanged(arc::mojom::TextInputType type) override;
   void OnCursorRectChanged(arc::mojom::CursorRectPtr rect) override;
   void OnCancelComposition() override;
   void ShowImeIfNeeded() override;
 
  private:
   mojo::Binding<mojom::ImeHost> binding_;
   Delegate* const delegate_;
   ArcBridgeService* const bridge_service_;
 
   DISALLOW_COPY_AND_ASSIGN(ArcImeBridgeImpl);
 };
 
 }  // namespace arc
 
 #endif  // COMPONENTS_ARC_IME_ARC_IME_BRIDGE_IMPL_H_