Fix NPE in pauseWebViewTimers

    Bug: http://b/issue?id=3225410
    added Tab parameter to pauseWebViewTimers
    removed unnecessary activityPaused parameter
    ensure tab is not null when called
    removed pauseCurrentTab method in TabControl

    changed resumeWebViewTimers to be consistent
    removed resumeCurrentTab from TabControl

Change-Id: I1cdf6042aa4df4c832d91c5a19d7235d6dce2b5d

1 files changed, 32 insertions, 22 deletions

diff --git a/src/com/android/browser/Controller.java b/src/com/android/browser/Controller.java
index b9bd9d73e..23921032f 100644
--- a/src/com/android/browser/Controller.java
+++ b/src/com/android/browser/Controller.java
@@ -548,13 +548,15 @@ public class Controller
             Log.e(LOGTAG, "BrowserActivity is already paused.");
             return;
         }
-        mTabControl.pauseCurrentTab();
         mActivityPaused = true;
-        if (mTabControl.getCurrentIndex() >= 0 &&
-                !pauseWebViewTimers(mActivityPaused)) {
-            mWakeLock.acquire();
-            mHandler.sendMessageDelayed(mHandler
-                    .obtainMessage(RELEASE_WAKELOCK), WAKELOCK_TIMEOUT);
+        Tab tab = mTabControl.getCurrentTab();
+        if (tab != null) {
+            tab.pause();
+            if (!pauseWebViewTimers(tab)) {
+                mWakeLock.acquire();
+                mHandler.sendMessageDelayed(mHandler
+                        .obtainMessage(RELEASE_WAKELOCK), WAKELOCK_TIMEOUT);
+            }
         }
         mUi.onPause();
         mNetworkHandler.onPause();
@@ -580,10 +582,12 @@ public class Controller
             Log.e(LOGTAG, "BrowserActivity is already resumed.");
             return;
         }
-        mTabControl.resumeCurrentTab();
         mActivityPaused = false;
-        resumeWebViewTimers();
-
+        Tab current = mTabControl.getCurrentTab();
+        if (current != null) {
+            current.resume();
+            resumeWebViewTimers(current);
+        }
         if (mWakeLock.isHeld()) {
             mHandler.removeMessages(RELEASE_WAKELOCK);
             mWakeLock.release();
@@ -593,9 +597,11 @@ public class Controller
         WebView.enablePlatformNotifications();
     }
 
-    private void resumeWebViewTimers() {
-        Tab tab = mTabControl.getCurrentTab();
-        if (tab == null) return; // monkey can trigger this
+    /**
+     * resume all WebView timers using the WebView instance of the given tab 
+     * @param tab guaranteed non-null
+     */
+    private void resumeWebViewTimers(Tab tab) {
         boolean inLoad = tab.inPageLoad();
         if ((!mActivityPaused && !inLoad) || (mActivityPaused && inLoad)) {
             CookieSyncManager.getInstance().startSync();
@@ -606,19 +612,23 @@ public class Controller
         }
     }
 
-    private boolean pauseWebViewTimers(boolean activityPaused) {
-        Tab tab = mTabControl.getCurrentTab();
-        boolean inLoad = tab.inPageLoad();
-        if (activityPaused && !inLoad) {
+    /**
+     * Pause all WebView timers using the WebView of the given tab
+     * @param tab
+     * @return true if the timers are paused or tab is null
+     */
+    private boolean pauseWebViewTimers(Tab tab) {
+        if (tab == null) {
+            return true;
+        } else if (!tab.inPageLoad()) {
             CookieSyncManager.getInstance().stopSync();
             WebView w = getCurrentWebView();
             if (w != null) {
                 w.pauseTimers();
             }
             return true;
-        } else {
-            return false;
         }
+        return false;
     }
 
     void onDestroy() {
@@ -713,7 +723,7 @@ public class Controller
         // to start the timer. As we won't switch tabs while an activity is in
         // pause state, we can ensure calling resume and pause in pair.
         if (mActivityPaused) {
-            resumeWebViewTimers();
+            resumeWebViewTimers(tab);
         }
         mLoadStopped = false;
         if (!mNetworkHandler.isNetworkUp()) {
@@ -754,7 +764,7 @@ public class Controller
         }
         // pause the WebView timer and release the wake lock if it is finished
         // while BrowserActivity is in pause state.
-        if (mActivityPaused && pauseWebViewTimers(mActivityPaused)) {
+        if (mActivityPaused && pauseWebViewTimers(tab)) {
             if (mWakeLock.isHeld()) {
                 mHandler.removeMessages(RELEASE_WAKELOCK);
                 mWakeLock.release();
@@ -2317,7 +2327,7 @@ public class Controller
                     // force the tab's inLoad() to be false as we are going to
                     // either finish the activity or remove the tab. This will
                     // ensure pauseWebViewTimers() taking action.
-                    mTabControl.getCurrentTab().clearInPageLoad();
+                    current.clearInPageLoad();
                     if (mTabControl.getTabCount() == 1) {
                         mActivity.finish();
                         return;
@@ -2326,7 +2336,7 @@ public class Controller
                         Log.e(LOGTAG, "BrowserActivity is already paused "
                                 + "while handing goBackOnePageOrQuit.");
                     }
-                    pauseWebViewTimers(true);
+                    pauseWebViewTimers(current);
                     removeTab(current);
                 }
                 /*