aw: Cancel pending callbacks after native destroy

Normal destroy already calls removeCallbacksAndMessages. This Cl covers
when the CleanupReference runs before the java side is garbage
collected.

Add a test for this, and stop this test suite repeating since they are
only unit tests.

Review-Url: https://codereview.chromium.org/2292393002
Cr-Commit-Position: refs/heads/master@{#415629}

android_webview/java/src/org/chromium/android_webview/AwContents.java

@@ -759,6 +759,13 @@ public class AwContents implements SmartClipProvider,
         mInitialFunctor = new AwGLFunctor(mNativeDrawGLFunctorFactory, mContainerView);
         mCurrentFunctor = mInitialFunctor;
         mContentsClient = contentsClient;
+        mContentsClient.getCallbackHelper().setCancelCallbackPoller(
+                new AwContentsClientCallbackHelper.CancelCallbackPoller() {
+                    @Override
+                    public boolean cancelAllCallbacks() {
+                        return AwContents.this.isDestroyed(NO_WARN);
+                    }
+                });
         mAwViewMethods = new AwViewMethodsImpl();
         mFullScreenTransitionsState = new FullScreenTransitionsState(
                 mContainerView, mInternalAccessAdapter, mAwViewMethods);
@@ -1218,12 +1225,7 @@ public class AwContents implements SmartClipProvider,
      * @return whether this instance of WebView is flagged as destroyed.
      */
     private boolean isDestroyed(int warnIfDestroyed) {
-        if (!mIsDestroyed) {
-            assert mContentViewCore != null;
-            assert mWebContents != null;
-            assert mNavigationController != null;
-            assert mNativeAwContents != 0;
-        } else if (warnIfDestroyed == WARN) {
+        if (mIsDestroyed && warnIfDestroyed == WARN) {
             Log.w(TAG, "Application attempted to call on a destroyed WebView", new Throwable());
         }
         boolean destroyRunnableHasRun =

android_webview/java/src/org/chromium/android_webview/AwContentsClientCallbackHelper.java

@@ -22,6 +22,12 @@ import java.util.concurrent.Callable;
  */
 @VisibleForTesting
 public class AwContentsClientCallbackHelper {
+    /**
+     * Interface to tell CallbackHelper to cancel posted callbacks.
+     */
+    public static interface CancelCallbackPoller {
+        boolean cancelAllCallbacks();
+    }
 
     // TODO(boliu): Consider removing DownloadInfo and LoginRequestInfo by using native
     // MessageLoop to post directly to AwContents.
@@ -126,6 +132,8 @@ public class AwContentsClientCallbackHelper {
 
     private final Handler mHandler;
 
+    private CancelCallbackPoller mCancelCallbackPoller;
+
     private class MyHandler extends Handler {
         private MyHandler(Looper looper) {
             super(looper);
@@ -133,6 +141,11 @@ public class AwContentsClientCallbackHelper {
 
         @Override
         public void handleMessage(Message msg) {
+            if (mCancelCallbackPoller != null && mCancelCallbackPoller.cancelAllCallbacks()) {
+                removeCallbacksAndMessages(null);
+                return;
+            }
+
             switch(msg.what) {
                 case MSG_ON_LOAD_RESOURCE: {
                     final String url = (String) msg.obj;
@@ -227,6 +240,11 @@ public class AwContentsClientCallbackHelper {
         mContentsClient = contentsClient;
     }
 
+    // Public for tests.
+    public void setCancelCallbackPoller(CancelCallbackPoller poller) {
+        mCancelCallbackPoller = poller;
+    }
+
     public void postOnLoadResource(String url) {
         mHandler.sendMessage(mHandler.obtainMessage(MSG_ON_LOAD_RESOURCE, url));
     }

android_webview/javatests/src/org/chromium/android_webview/test/AwContentsClientCallbackHelperTest.java

@@ -15,6 +15,7 @@ import org.chromium.android_webview.test.TestAwContentsClient.OnDownloadStartHel
 import org.chromium.android_webview.test.TestAwContentsClient.OnReceivedLoginRequestHelper;
 import org.chromium.android_webview.test.TestAwContentsClient.PictureListenerHelper;
 import org.chromium.base.test.util.Feature;
+import org.chromium.base.test.util.parameter.ParameterizedTest;
 import org.chromium.content.browser.test.util.CallbackHelper;
 import org.chromium.content.browser.test.util.TestCallbackHelperContainer.OnPageStartedHelper;
 import org.chromium.content.browser.test.util.TestCallbackHelperContainer.OnReceivedErrorHelper;
@@ -24,6 +25,7 @@ import java.util.concurrent.Callable;
 /**
  * Test suite for AwContentsClientCallbackHelper.
  */
+@ParameterizedTest.Set  // These are unit tests. No need to repeat for multiprocess.
 public class AwContentsClientCallbackHelperTest extends AwTestBase {
     /**
      * Callback helper for OnLoadedResource.
@@ -65,6 +67,26 @@ public class AwContentsClientCallbackHelperTest extends AwTestBase {
         }
     }
 
+    private static class TestCancelCallbackPoller
+            implements AwContentsClientCallbackHelper.CancelCallbackPoller {
+        private boolean mCancelled;
+        private final CallbackHelper mCallbackHelper = new CallbackHelper();
+
+        public void setCancelled() {
+            mCancelled = true;
+        }
+
+        public CallbackHelper getCallbackHelper() {
+            return mCallbackHelper;
+        }
+
+        @Override
+        public boolean cancelAllCallbacks() {
+            mCallbackHelper.notifyCalled();
+            return mCancelled;
+        }
+    }
+
     static final int PICTURE_TIMEOUT = 5000;
     static final String TEST_URL = "www.example.com";
     static final String REALM = "www.example.com";
@@ -82,6 +104,7 @@ public class AwContentsClientCallbackHelperTest extends AwTestBase {
 
     private TestAwContentsClient mContentsClient;
     private AwContentsClientCallbackHelper mClientHelper;
+    private TestCancelCallbackPoller mCancelCallbackPoller;
     private Looper mLooper;
 
     @Override
@@ -90,6 +113,8 @@ public class AwContentsClientCallbackHelperTest extends AwTestBase {
         mLooper = Looper.getMainLooper();
         mContentsClient = new TestAwContentsClient();
         mClientHelper = new AwContentsClientCallbackHelper(mLooper, mContentsClient);
+        mCancelCallbackPoller = new TestCancelCallbackPoller();
+        mClientHelper.setCancelCallbackPoller(mCancelCallbackPoller);
     }
 
     @Feature({"AndroidWebView"})
@@ -226,4 +251,31 @@ public class AwContentsClientCallbackHelperTest extends AwTestBase {
         assertEquals(OLD_SCALE, scaleChangedHelper.getOldScale());
         assertEquals(NEW_SCALE, scaleChangedHelper.getNewScale());
     }
+
+    @Feature({"AndroidWebView"})
+    @SmallTest
+    public void testCancelCallbackPoller() throws Exception {
+        mCancelCallbackPoller.setCancelled();
+        CallbackHelper cancelCallbackPollerHelper = mCancelCallbackPoller.getCallbackHelper();
+        OnPageStartedHelper pageStartedHelper = mContentsClient.getOnPageStartedHelper();
+
+        int pollCount = pageStartedHelper.getCallCount();
+        int onPageStartedCount = pageStartedHelper.getCallCount();
+        // Post two callbacks.
+        mClientHelper.postOnPageStarted(TEST_URL);
+        mClientHelper.postOnPageStarted(TEST_URL);
+
+        // Wait for at least one poll.
+        cancelCallbackPollerHelper.waitForCallback(pollCount);
+
+        // Flush main queue.
+        getInstrumentation().runOnMainSync(new Runnable() {
+            @Override
+            public void run() {
+            }
+        });
+
+        // Neither callback should actually happen.
+        assertEquals(onPageStartedCount, pageStartedHelper.getCallCount());
+    }
 }