Use a resource throttle to implement shouldOverrideUrlLoading.

content/public/android/java/src/org/chromium/content/browser/webcontents/WebContentsObserverProxy.java

 // Copyright 2015 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.content.browser.webcontents;
 
 import org.chromium.base.CalledByNative;
 import org.chromium.base.JNINamespace;
 import org.chromium.base.ObserverList;
 import org.chromium.base.ObserverList.RewindableIterator;
@@ skipping 76 matching lines @@
     @CalledByNative
     public void didStopLoading(String url) {
         for (mObserversIterator.rewind(); mObserversIterator.hasNext();) {
             mObserversIterator.next().didStopLoading(url);
         }
     }
 
     @Override
     @CalledByNative
     public void didFailLoad(boolean isProvisionalLoad, boolean isMainFrame, int errorCode,
-            String description, String failingUrl) {
+            String description, String failingUrl, boolean wasIgnoredByHandler) {
         for (mObserversIterator.rewind(); mObserversIterator.hasNext();) {
-            mObserversIterator.next().didFailLoad(
-                    isProvisionalLoad, isMainFrame, errorCode, description, failingUrl);
+            mObserversIterator.next().didFailLoad(isProvisionalLoad, isMainFrame, errorCode,
+                    description, failingUrl, wasIgnoredByHandler);
         }
     }
 
     @Override
     @CalledByNative
     public void didNavigateMainFrame(String url, String baseUrl,
             boolean isNavigationToDifferentPage, boolean isFragmentNavigation, int statusCode) {
         for (mObserversIterator.rewind(); mObserversIterator.hasNext();) {
             mObserversIterator.next().didNavigateMainFrame(
                     url, baseUrl, isNavigationToDifferentPage, isFragmentNavigation, statusCode);
@@ skipping 117 matching lines @@
 
         if (mNativeWebContentsObserverProxy != 0) {
             nativeDestroy(mNativeWebContentsObserverProxy);
             mNativeWebContentsObserverProxy = 0;
         }
     }
 
     private native long nativeInit(WebContentsImpl webContents);
     private native void nativeDestroy(long nativeWebContentsObserverProxy);
 }