[Cronet] Add callback wrapper classes to enforce API version checking.

components/cronet/android/java/src/org/chromium/net/impl/CronetUrlRequest.java

 // Copyright 2014 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.net.impl;
 
 import org.chromium.base.Log;
 import org.chromium.base.VisibleForTesting;
 import org.chromium.base.annotations.CalledByNative;
 import org.chromium.base.annotations.JNIAdditionalImport;
@@ skipping 21 matching lines @@
 /**
  * UrlRequest using Chromium HTTP stack implementation. Could be accessed from
  * any thread on Executor. Cancel can be called from any thread.
  * All @CallByNative methods are called on native network thread
  * and post tasks with listener calls onto Executor. Upon return from listener
  * callback native request adapter is called on executive thread and posts
  * native tasks to native network thread. Because Cancel could be called from
  * any thread it is protected by mUrlRequestAdapterLock.
  */
 @JNINamespace("cronet")
-// Qualifies UrlRequest.StatusListener which is used in onStatus, a JNI method.
-@JNIAdditionalImport(UrlRequest.class)
+// Qualifies VersionSafeCallbacks.UrlRequestStatusListener which is used in onStatus, a JNI method.
+@JNIAdditionalImport(VersionSafeCallbacks.class)
 @VisibleForTesting
 public final class CronetUrlRequest extends UrlRequestBase {
     private final boolean mAllowDirectExecutor;
 
     /* Native adapter object, owned by UrlRequest. */
     @GuardedBy("mUrlRequestAdapterLock")
     private long mUrlRequestAdapter;
 
     @GuardedBy("mUrlRequestAdapterLock")
     private boolean mStarted = false;
@@ skipping 13 matching lines @@
     private final Executor mExecutor;
 
     /*
      * URL chain contains the URL currently being requested, and
      * all URLs previously requested. New URLs are added before
      * mCallback.onRedirectReceived is called.
      */
     private final List<String> mUrlChain = new ArrayList<String>();
     private long mReceivedBytesCountFromRedirects;
 
-    private final UrlRequest.Callback mCallback;
+    private final VersionSafeCallbacks.UrlRequestCallback mCallback;
     private final String mInitialUrl;
     private final int mPriority;
     private String mInitialMethod;
     private final HeadersList mRequestHeaders = new HeadersList();
     private final Collection<Object> mRequestAnnotations;
     @RequestFinishedInfoImpl.FinishedReason
     private int mFinishedReason;
     private UrlRequestException mException;
     private final boolean mDisableCache;
     private final boolean mDisableConnectionMigration;
@@ skipping 48 matching lines @@
         }
         if (executor == null) {
             throw new NullPointerException("Executor is required");
         }
 
         mAllowDirectExecutor = allowDirectExecutor;
         mRequestContext = requestContext;
         mInitialUrl = url;
         mUrlChain.add(url);
         mPriority = convertRequestPriority(priority);
-        mCallback = callback;
+        mCallback = new VersionSafeCallbacks.UrlRequestCallback(callback);
         mExecutor = executor;
         mRequestAnnotations = requestAnnotations;
         mDisableCache = disableCache;
         mDisableConnectionMigration = disableConnectionMigration;
     }
 
     @Override
     public void setHttpMethod(String method) {
         checkNotStarted();
         if (method == null) {
@@ skipping 150 matching lines @@
             return isDoneLocked();
         }
     }
 
     @GuardedBy("mUrlRequestAdapterLock")
     private boolean isDoneLocked() {
         return mStarted && mUrlRequestAdapter == 0;
     }
 
     @Override
-    public void getStatus(final UrlRequest.StatusListener listener) {
+    public void getStatus(UrlRequest.StatusListener unsafeListener) {
+        final VersionSafeCallbacks.UrlRequestStatusListener listener =
+                new VersionSafeCallbacks.UrlRequestStatusListener(unsafeListener);
         synchronized (mUrlRequestAdapterLock) {
             if (mUrlRequestAdapter != 0) {
                 nativeGetStatus(mUrlRequestAdapter, listener);
                 return;
             }
         }
         Runnable task = new Runnable() {
             @Override
             public void run() {
                 listener.onStatus(UrlRequest.Status.INVALID);
@@ skipping 340 matching lines @@
         };
         postTaskToExecutor(task);
     }
 
     /**
      * Called by the native code when request status is fetched from the
      * native stack.
      */
     @SuppressWarnings("unused")
     @CalledByNative
-    private void onStatus(final UrlRequest.StatusListener listener, final int loadState) {
+    private void onStatus(
+            final VersionSafeCallbacks.UrlRequestStatusListener listener, final int loadState) {
         Runnable task = new Runnable() {
             @Override
             public void run() {
                 listener.onStatus(convertLoadState(loadState));
             }
         };
         postTaskToExecutor(task);
     }
 
     /**
@@ skipping 81 matching lines @@
     private native void nativeFollowDeferredRedirect(long nativePtr);
 
     @NativeClassQualifiedName("CronetURLRequestAdapter")
     private native boolean nativeReadData(
             long nativePtr, ByteBuffer byteBuffer, int position, int capacity);
 
     @NativeClassQualifiedName("CronetURLRequestAdapter")
     private native void nativeDestroy(long nativePtr, boolean sendOnCanceled);
 
     @NativeClassQualifiedName("CronetURLRequestAdapter")
-    private native void nativeGetStatus(long nativePtr, UrlRequest.StatusListener listener);
+    private native void nativeGetStatus(
+            long nativePtr, VersionSafeCallbacks.UrlRequestStatusListener listener);
 }