Battery Status API: blink promise implementation and layout tests.

Source/modules/battery/NavigatorBattery.cpp

Index: Source/modules/battery/NavigatorBattery.cpp
diff --git a/Source/modules/battery/NavigatorBattery.cpp b/Source/modules/battery/NavigatorBattery.cpp
index caaff759521c652ec60c0a3cd7d7c2bc01d6a656..37e4bc40820b9a688911b96b90f9e40c1ec8265c 100644
--- a/Source/modules/battery/NavigatorBattery.cpp
+++ b/Source/modules/battery/NavigatorBattery.cpp
@@ -18,16 +18,20 @@ NavigatorBattery::~NavigatorBattery()
 {
 }
 
-BatteryManager* NavigatorBattery::battery(Navigator& navigator)
+ScriptPromise NavigatorBattery::getBattery(ScriptState* scriptState, Navigator& navigator)
 {
-    return NavigatorBattery::from(navigator).batteryManager(navigator);
+    return NavigatorBattery::from(navigator).getBattery(scriptState);
 }
 
-BatteryManager* NavigatorBattery::batteryManager(Navigator& navigator)
+ScriptPromise NavigatorBattery::getBattery(ScriptState* scriptState)
 {
-    if (!m_batteryManager && navigator.frame())
-        m_batteryManager = BatteryManager::create(navigator.frame()->document());
-    return m_batteryManager.get();
+    if (!m_batteryManager) {
+        m_batteryManager = BatteryManager::create(scriptState->executionContext());
+        // Create a wrapper to expose this object to the V8 GC so that hasPendingActivity takes effect.
+        toV8NoInline(m_batteryManager.get(), scriptState->context()->Global(), scriptState->isolate());

[abarth-chromium, 2014/06/11 19:44:34]

Why is this necessary?  We're already holding m_batteryManager...

[timvolodine, 2014/06/12 16:38:46]

Done.

+    }
+
+    return m_batteryManager->startRequest(scriptState);
 }
 
 const char* NavigatorBattery::supplementName()