Revert of Migrates battery_status from content/renderer/ to WebKit/platform/

third_party/WebKit/Source/modules/battery/BatteryDispatcher.cpp

 // 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.
 
 #include "modules/battery/BatteryDispatcher.h"
 
-#include "wtf/PassOwnPtr.h"
+#include "modules/battery/BatteryStatus.h"
+#include "public/platform/Platform.h"
 
 namespace blink {
 
+namespace {
+
+double ensureTwoSignificantDigits(double level)
+{
+    // Convert battery level value which should be in [0, 1] to a value in [0, 1]
+    // with 2 digits of precision. This is to provide a consistent experience
+    // across platforms (e.g. on Mac and Android the battery changes are generally
+    // reported with 1% granularity). It also serves the purpose of reducing the
+    // possibility of fingerprinting and triggers less level change events on
+    // platforms where the granularity is high.
+    ASSERT(level >= 0 && level <= 1);
+    return round(level * 100) / 100.f;
+}
+
+} // namespace
+
+
 BatteryDispatcher& BatteryDispatcher::instance()
 {
     DEFINE_STATIC_LOCAL(Persistent<BatteryDispatcher>, batteryDispatcher, (new BatteryDispatcher()));
     return *batteryDispatcher;
 }
 
 BatteryDispatcher::BatteryDispatcher()
-    : m_hasLatestData(false)
-    , m_batteryDispatcherProxy(adoptPtr(new BatteryDispatcherProxy(this)))
 {
 }
 
 BatteryDispatcher::~BatteryDispatcher()
 {
 }
 
-void BatteryDispatcher::OnUpdateBatteryStatus(const BatteryStatus& batteryStatus)
+DEFINE_TRACE(BatteryDispatcher)
 {
-    m_batteryStatus = batteryStatus;
-    m_hasLatestData = true;
+    visitor->trace(m_batteryStatus);
+    PlatformEventDispatcher::trace(visitor);
+}
+
+void BatteryDispatcher::updateBatteryStatus(const WebBatteryStatus& batteryStatus)
+{
+    m_batteryStatus = BatteryStatus::create(
+        batteryStatus.charging, batteryStatus.chargingTime, batteryStatus.dischargingTime,
+        ensureTwoSignificantDigits(batteryStatus.level));
     notifyControllers();
 }
 
+BatteryStatus* BatteryDispatcher::latestData()
+{
+    return m_batteryStatus.get();
+}
+
 void BatteryDispatcher::startListening()
 {
-    m_batteryDispatcherProxy->StartListening();
+    Platform::current()->startListening(WebPlatformEventTypeBattery, this);
 }
 
 void BatteryDispatcher::stopListening()
 {
-    m_batteryDispatcherProxy->StopListening();
-    m_hasLatestData = false;
+    Platform::current()->stopListening(WebPlatformEventTypeBattery);
+    m_batteryStatus.clear();
 }
 
 } // namespace blink