Pass format as argument to getContentBitmapAsync.

content/public/android/java/src/org/chromium/content/browser/ContentReadbackHandler.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.content.browser;
 
 import android.graphics.Bitmap;
 import android.graphics.Rect;
 import android.util.SparseArray;
 
@@ skipping 63 matching lines @@
      * Asynchronously, generate and grab a bitmap representing what is currently on the screen
      * for {@code view}.
      *
      * @param scale The scale that should be applied to the content.
      * @param srcRect  A subrect of the original content to capture. If this is empty, it will grab
      *                 the whole surface.
      * @param view  The {@link ContentViewCore} to grab the bitmap from.
      * @param callback The callback to be executed after readback completes.
      */
     public void getContentBitmapAsync(float scale, Rect srcRect, ContentViewCore view,
-            GetBitmapCallback callback) {
+            Bitmap.Config config, GetBitmapCallback callback) {

[Yaron, 2015/03/25 14:13:56]

You need to update the javadoc accordingly

         if (!readyForReadback()) {
             callback.onFinishGetBitmap(null);
             return;
         }
         ThreadUtils.assertOnUiThread();
 
         int readbackId = mNextReadbackId++;
         mGetBitmapRequests.put(readbackId, callback);
         nativeGetContentBitmap(mNativeContentReadbackHandler, readbackId, scale,
-                Bitmap.Config.ARGB_8888, srcRect.top, srcRect.left, srcRect.width(),
+                config, srcRect.top, srcRect.left, srcRect.width(),
                 srcRect.height(), view);
     }
 
     /**
      * Asynchronously, grab a bitmap of the current browser compositor root layer.
      *
      * @param windowAndroid The window that hosts the compositor.
      * @param callback      The callback to be executed after readback completes.
      */
     public void getCompositorBitmapAsync(WindowAndroid windowAndroid, GetBitmapCallback callback) {
@@ skipping 16 matching lines @@
     protected abstract boolean readyForReadback();
 
     private native long nativeInit();
     private native void nativeDestroy(long nativeContentReadbackHandler);
     private native void nativeGetContentBitmap(long nativeContentReadbackHandler, int readbackId,
             float scale, Bitmap.Config config, float x, float y, float width, float height,
             Object contentViewCore);
     private native void nativeGetCompositorBitmap(long nativeContentReadbackHandler,
             int readbackId, long nativeWindowAndroid);
 }