Implement the content/renderer and content/browser part of the Device Motion API.

content/renderer/device_orientation/device_motion_event_pump.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 "device_motion_event_pump.h"
+
+#include "base/bind.h"
+#include "base/logging.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/message_loop.h"
+#include "base/shared_memory.h"
+#include "device_motion_shared_memory_reader.h"
+#include "third_party/WebKit/Source/Platform/chromium/public/WebDeviceMotionData.h"
+#include "third_party/WebKit/Source/Platform/chromium/public/WebDeviceMotionListener.h"
+
+namespace content {
+
+const double DeviceMotionEventPump::kPumpDelayMillis = 40;
+
+DeviceMotionEventPump::DeviceMotionEventPump()
+    : listener_(0) {
+}
+
+DeviceMotionEventPump::~DeviceMotionEventPump() {
+}
+
+void DeviceMotionEventPump::setListener(
+    WebKit::WebDeviceMotionListener* listener) {
+  listener_ = listener;
+  listener_ ? startFetchingDeviceMotion() : stopFetchingDeviceMotion();
+}
+
+void DeviceMotionEventPump::setDeviceMotionReader(
+    DeviceMotionSharedMemoryReader* reader) {
+  reader_.reset(reader);
+}
+
+void DeviceMotionEventPump::startFetchingDeviceMotion() {
+  DVLOG(2) << "start fetching device motion";
+  if (timer_.IsRunning())
+    return;
+
+  if (!reader_.get())
+    setDeviceMotionReader(new DeviceMotionSharedMemoryReader);
+
+  reader_->startUpdating();
+  timer_.Start(FROM_HERE, base::TimeDelta::FromMilliseconds(kPumpDelayMillis),
+                 this, &DeviceMotionEventPump::fireEvent);

[darin (slow to review), 2013/05/29 06:41:53]

nit: fix indentation

[timvolodine, 2013/05/29 18:59:06]

Done.

+}
+
+void DeviceMotionEventPump::stopFetchingDeviceMotion() {
+  DVLOG(2) << "stop fetching device motion";
+  if (timer_.IsRunning()) {
+    timer_.Stop();
+    reader_->stopUpdating();
+  }
+}
+
+void DeviceMotionEventPump::fireEvent() {
+  DCHECK(listener_);
+  WebKit::WebDeviceMotionData data;
+  if (reader_->latestDeviceMotionData(data))
+    listener_->didChangeDeviceMotion(data);
+}
+
+void DeviceMotionEventPump::didChangeDeviceMotion(
+    const WebKit::WebDeviceMotionData& data) {
+  NOTIMPLEMENTED();

[darin (slow to review), 2013/05/29 06:41:53]

add a comment?  why is DeviceMotionEventPump extending from
WebDeviceMotionListener if it is not going to implement this method?

[timvolodine, 2013/05/29 18:59:06]

actually the listener interface is no longer relevant here, so removed it.
Done.

+}
+
+}  // namespace content