Use a resource throttle to implement shouldOverrideUrlLoading.

content/public/android/java/src/org/chromium/content/browser/ContentViewCore.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.content.browser;
 
 import android.annotation.SuppressLint;
 import android.annotation.TargetApi;
 import android.app.Activity;
 import android.app.SearchManager;
@@ skipping 291 matching lines @@
         // Using a weak reference avoids cycles that might prevent GC of WebView's WebContents.
         private final WeakReference<ContentViewCore> mWeakContentViewCore;
 
         ContentViewWebContentsObserver(ContentViewCore contentViewCore) {
             super(contentViewCore.getWebContents());
             mWeakContentViewCore = new WeakReference<ContentViewCore>(contentViewCore);
         }
 
         @Override
         public void didFailLoad(boolean isProvisionalLoad, boolean isMainFrame, int errorCode,
-                String description, String failingUrl) {
+                String description, String failingUrl, boolean wasIgnoredByHandler) {
             // Navigation that fails the provisional load will have the strong binding removed
             // here. One for which the provisional load is commited will have the strong binding
             // removed in navigationEntryCommitted() below.
             if (isProvisionalLoad) determinedProcessVisibility();
         }
 
         @Override
         public void didNavigateMainFrame(String url, String baseUrl,
                 boolean isNavigationToDifferentPage, boolean isFragmentNavigation, int statusCode) {
             if (!isNavigationToDifferentPage) return;
@@ skipping 2892 matching lines @@
             String textTrackFontVariant, String textTrackTextColor, String textTrackTextShadow,
             String textTrackTextSize);
 
     private native void nativeExtractSmartClipData(long nativeContentViewCoreImpl,
             int x, int y, int w, int h);
 
     private native void nativeSetBackgroundOpaque(long nativeContentViewCoreImpl, boolean opaque);
 
     private native void nativeSetDrawsContent(long nativeContentViewCoreImpl, boolean draws);
 }