Remove Battery Status API support code from Blink

LayoutTests/batterystatus/script-tests/updates.js

-description('Tests that updates to the battery event causes new events to fire.');
-
-var charging = false;
-var chargingTime = Number.POSITIVE_INFINITY;
-var dischargingTime = 6000;
-var level = 0.7;
-
-var battery = navigator.webkitBattery;
-
-function checkBatteryStatus() {
-    shouldBe("battery.charging", "false");
-    shouldBe("battery.chargingTime", "Infinity");
-    shouldBe("battery.dischargingTime", "6000");
-    shouldBe("battery.level", "0.7");
-}
-
-function setBatteryStatus() {
-    internals.setBatteryStatus(document, 'chargingchange', charging, chargingTime, dischargingTime, level);
-}
-
-function firstListener() {
-    checkBatteryStatus();
-    battery.removeEventListener('chargingchange', firstListener);
-    battery.addEventListener('chargingchange', updateListener);
-    charging = true;
-    chargingTime = 7000;
-    dischargingTime = Number.POSITIVE_INFINITY;
-    level = 0.3;
-        setBatteryStatus();
-}
-
-function updateListener(event) {
-    shouldBe("battery.charging", "true");
-    shouldBe("battery.chargingTime", "7000");
-    shouldBe("battery.dischargingTime", "Infinity");
-    shouldBe("battery.level", "0.3");
-    finishJSTest();
-}
-
-battery.addEventListener('chargingchange', firstListener);
-setBatteryStatus();
-window.jsTestIsAsync = true;