Plumbs through android supplying multipe touch points

services/native_viewport/native_viewport_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 SERVICES_NATIVE_VIEWPORT_NATIVE_VIEWPORT_IMPL_H_
 #define SERVICES_NATIVE_VIEWPORT_NATIVE_VIEWPORT_IMPL_H_
 
+#include <set>
+
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "mojo/public/cpp/bindings/strong_binding.h"
 #include "mojo/services/gpu/public/interfaces/gpu.mojom.h"
 #include "mojo/services/native_viewport/public/interfaces/native_viewport.mojom.h"
 #include "services/native_viewport/onscreen_context_provider.h"
 #include "services/native_viewport/platform_viewport.h"
 #include "ui/gfx/geometry/rect.h"
 
 namespace gles2 {
@@ skipping 34 matching lines @@
   // PlatformViewport::Delegate implementation.
   void OnMetricsChanged(mojo::ViewportMetricsPtr metrics) override;
   void OnAcceleratedWidgetAvailable(gfx::AcceleratedWidget widget) override;
   void OnAcceleratedWidgetDestroyed() override;
   bool OnEvent(mojo::EventPtr event) override;
   void OnDestroyed() override;
 
   // mojo::ErrorHandler implementation.
   void OnConnectionError() override;
 
-  void AckEvent();
+ private:
+  // Callback when the dispatcher has processed a message we're waiting on
+  // an ack from. |pointer_id| identifies the pointer the message was associated
+  // with.
+  void AckEvent(int32 pointer_id);
 
- private:
   bool is_headless_;
   scoped_ptr<PlatformViewport> platform_viewport_;
   OnscreenContextProvider context_provider_;
   bool sent_metrics_;
   mojo::ViewportMetricsPtr metrics_;
-  bool waiting_for_event_ack_;
   CreateCallback create_callback_;
   RequestMetricsCallback metrics_callback_;
   mojo::NativeViewportEventDispatcherPtr event_dispatcher_;
   mojo::Binding<mojo::NativeViewport> binding_;
   base::WeakPtrFactory<NativeViewportImpl> weak_factory_;
 
+  // Set of pointer_ids we've sent a move to and are waiting on an ack.
+  std::set<int32> pointers_waiting_on_ack_;
+
   DISALLOW_COPY_AND_ASSIGN(NativeViewportImpl);
 };
 
 }  // namespace native_viewport
 
 #endif  // SERVICES_NATIVE_VIEWPORT_NATIVE_VIEWPORT_IMPL_H_