Implement Android shared memory data fetcher for Device Motion.

content/browser/device_orientation/data_fetcher_impl_win.cc

 // Copyright (c) 2013 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/device_orientation/data_fetcher_impl_win.h"
 
 #include <InitGuid.h>
 #include <PortableDeviceTypes.h>
 #include <Sensors.h>
 
@@ skipping 83 matching lines @@
   STDMETHODIMP OnStateChanged(ISensor* sensor, SensorState state) OVERRIDE {
     return S_OK;
   }
 
  private:
   DataFetcherImplWin* const fetcher_;
 
   DISALLOW_COPY_AND_ASSIGN(SensorEventSink);
 };
 
+DataFetcherImplWin* DataFetcherImplWin::instance() {
+  CR_DEFINE_STATIC_LOCAL(DataFetcherImplWin, s_data_fetcher, ());
+  return &s_data_fetcher;
+}
+
 // Create a DataFetcherImplWin object and return NULL if no valid sensor found.
 // static
 DataFetcher* DataFetcherImplWin::Create() {
-  scoped_ptr<DataFetcherImplWin> fetcher(new DataFetcherImplWin);
+  DataFetcherImplWin* fetcher = DataFetcherImplWin::instance();
   if (fetcher->Initialize())
-    return fetcher.release();
+    return fetcher;
 
   LOG(ERROR) << "DataFetcherImplWin::Initialize failed!";
   return NULL;
 }
 
 DataFetcherImplWin::~DataFetcherImplWin() {
-  if (sensor_)
-    sensor_->SetEventSink(NULL);
+  Stop();
 }
 
 DataFetcherImplWin::DataFetcherImplWin() {
 }
 
+void DataFetcherImplWin::Stop() {
+  if (sensor_)
+    sensor_->SetEventSink(NULL);
+}
+
 void DataFetcherImplWin::OnOrientationData(Orientation* orientation) {
   // This method is called on Windows sensor thread.
   base::AutoLock autolock(next_orientation_lock_);
   next_orientation_ = orientation;
 }
 
 const DeviceData* DataFetcherImplWin::GetDeviceData(DeviceData::Type type) {
   if (type != DeviceData::kTypeOrientation)
     return NULL;
   return GetOrientation();
@@ skipping 51 matching lines @@
     return false;
 
   hr = sensor_->SetEventSink(sensor_events);
   if (FAILED(hr))
     return false;
 
   return true;
 }
 
 }  // namespace content