Stop the loading after WAKELOCK_TIMEOUT (5min) when
the Browser is in the background. So we won't continue to
burn the battery if there is some mis-behaved JavaScript
running.

Fix http://b/issue?id=2147840
diff --git a/src/com/android/browser/BrowserActivity.java b/src/com/android/browser/BrowserActivity.java
index a66334b..78664a0 100644
--- a/src/com/android/browser/BrowserActivity.java
+++ b/src/com/android/browser/BrowserActivity.java
@@ -2380,6 +2380,10 @@
                 case RELEASE_WAKELOCK:
                     if (mWakeLock.isHeld()) {
                         mWakeLock.release();
+                        // if we reach here, Browser should be still in the
+                        // background loading after WAKELOCK_TIMEOUT (5-min).
+                        // To avoid burning the battery, stop loading.
+                        mTabControl.stopAllLoading();
                     }
                     break;