Use a resource throttle to implement shouldOverrideUrlLoading.

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

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package org.chromium.android_webview;
 
 import android.annotation.SuppressLint;
 import android.app.Activity;
 import android.content.ComponentCallbacks2;
 import android.content.Context;
@@ skipping 454 matching lines @@
     // callback to the correct WebViewClient that is associated with the WebView.
     // Otherwise, use this delegate only to post onPageStarted messages.
     //
     // We are not using WebContentsObserver.didStartLoading because of stale URLs, out of order
     // onPageStarted's and double onPageStarted's.
     //
     private class InterceptNavigationDelegateImpl implements InterceptNavigationDelegate {
         @Override
         public boolean shouldIgnoreNavigation(NavigationParams navigationParams) {
             final String url = navigationParams.url;
+
+            final int transitionType = navigationParams.pageTransitionType;
+            final boolean isLoadUrl =
+                    (transitionType & PageTransition.FROM_API) != 0;
+            final boolean isBackForward =
+                    (transitionType & PageTransition.FORWARD_BACK) != 0;
+            final boolean isReload =
+                    (transitionType & PageTransition.CORE_MASK) == PageTransition.RELOAD;
+            final boolean isRedirect = navigationParams.isRedirect;
+
             boolean ignoreNavigation = false;
-            if (mDeferredShouldOverrideUrlLoadingIsPendingForPopup) {
-                mDeferredShouldOverrideUrlLoadingIsPendingForPopup = false;
+            // Any navigation from loadUrl, goBack/Forward, or reload, are considered application
+            // initiated and hence will not yield a shouldOverrideUrlLoading() callback.
+            if ((isLoadUrl && !isRedirect) || isBackForward) {
                 // If this is used for all navigations in future, cases for application initiated
                 // load, redirect and backforward should also be filtered out.

[sgurun-gerrit only, 2015/06/05 07:52:49]

no-op if expression is true? you should be able to combine the expressions.

[gsennton, 2015/06/08 14:07:23]

Done.

-                if (!navigationParams.isPost) {
-                    ignoreNavigation = mContentsClient.shouldOverrideUrlLoading(url);
-                }
+            } else if (!navigationParams.isPost) {
+                ignoreNavigation = mContentsClient.shouldOverrideUrlLoading(url);
             }
+
             // The shouldOverrideUrlLoading call might have resulted in posting messages to the
             // UI thread. Using sendMessage here (instead of calling onPageStarted directly)
             // will allow those to run in order.
-            if (!ignoreNavigation) {
+            if (isRedirect) {
+                mContentsClient.getCallbackHelper().postOnPageStarted(url);
+                // We can post onPageFinished here since we know that the navigation will fail.
+                // Also AwWebContentsObserver.didFail does not call OnPageFinished when the
+                // navigation is overridden because we don't want an onPageFinished for such a
+                // navigation unless it is a redirect.
+                if (ignoreNavigation) {
+                    mContentsClient.getCallbackHelper().postOnPageFinished(url);
+                }
+            } else if (!ignoreNavigation) {
                 mContentsClient.getCallbackHelper().postOnPageStarted(url);
             }
             return ignoreNavigation;
         }
     }
 
     //--------------------------------------------------------------------------------------------
     private class AwLayoutSizerDelegate implements AwLayoutSizer.Delegate {
         @Override
         public void requestLayout() {
@@ skipping 2569 matching lines @@
     private native void nativeCreatePdfExporter(long nativeAwContents, AwPdfExporter awPdfExporter);
 
     private native void nativePreauthorizePermission(long nativeAwContents, String origin,
             long resources);
 
     private native void nativePostMessageToFrame(long nativeAwContents, String frameId,
             String message, String targetOrigin, int[] msgPorts);
 
     private native void nativeCreateMessageChannel(long nativeAwContents, AwMessagePort[] ports);
 }