Battery Status API: add testing support for LayoutTests.

content/shell/renderer/test_runner/test_runner.h

Index: content/shell/renderer/test_runner/test_runner.h
diff --git a/content/shell/renderer/test_runner/test_runner.h b/content/shell/renderer/test_runner/test_runner.h
index e5d599476e2e4e803a039235219b07105956dd9d..a2d96abce25c547c9025de6e08518cc4e4fbcaef 100644
--- a/content/shell/renderer/test_runner/test_runner.h
+++ b/content/shell/renderer/test_runner/test_runner.h
@@ -300,6 +300,11 @@ class TestRunner : public WebTestRunner,
 
   void SetMockScreenOrientation(const std::string& orientation);
 
+  void DidChangeBatteryStatus(bool charging,
+                              double chargingTime,
+                              double dischargingTime,
+                              double level);
+
   void DidAcquirePointerLock();
   void DidNotAcquirePointerLock();
   void DidLosePointerLock();