android: add Java-side support for browser compositor async readback

ui/android/java/src/org/chromium/ui/base/ActivityWindowAndroid.java

Index: ui/android/java/src/org/chromium/ui/base/ActivityWindowAndroid.java
diff --git a/ui/android/java/src/org/chromium/ui/base/ActivityWindowAndroid.java b/ui/android/java/src/org/chromium/ui/base/ActivityWindowAndroid.java
index 99c8c415190a9968d289c7584ffd42e91b930239..07f48dcc13f3248fa107f146abd0de462dbd2944 100644
--- a/ui/android/java/src/org/chromium/ui/base/ActivityWindowAndroid.java
+++ b/ui/android/java/src/org/chromium/ui/base/ActivityWindowAndroid.java
@@ -9,14 +9,7 @@ import android.app.PendingIntent;
 import android.content.ActivityNotFoundException;
 import android.content.Intent;
 import android.content.IntentSender.SendIntentException;
-import android.graphics.Bitmap;
-import android.graphics.Rect;
-import android.util.Log;
-import android.view.View;
 
-import org.chromium.ui.UiUtils;
-
-import java.io.ByteArrayOutputStream;
 import java.lang.ref.WeakReference;
 
 /**
@@ -105,41 +98,6 @@ public class ActivityWindowAndroid extends WindowAndroid {
         return new WeakReference<Activity>(mActivityRef.get());
     }
 
-    /**
-     * Returns a PNG-encoded screenshot of the the window region at (|windowX|,
-     * |windowY|) with the size |width| by |height| pixels.
-     */
-    @Override
-    public byte[] grabSnapshot(int windowX, int windowY, int width, int height) {
-        Activity activity = mActivityRef.get();
-        if (activity == null) return null;
-        try {
-            // Take a screenshot of the root activity view. This generally includes UI
-            // controls such as the URL bar and OS windows such as the status bar.
-            View rootView = activity.findViewById(android.R.id.content).getRootView();
-            Bitmap bitmap = UiUtils.generateScaledScreenshot(rootView, 0, Bitmap.Config.ARGB_8888);
-            if (bitmap == null) return null;
-
-            // Clip the result into the requested region.
-            if (windowX > 0 || windowY > 0 || width != bitmap.getWidth() ||
-                    height != bitmap.getHeight()) {
-                Rect clip = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());
-                clip.intersect(windowX, windowY, windowX + width, windowY + height);
-                bitmap = Bitmap.createBitmap(
-                        bitmap, clip.left, clip.top, clip.width(), clip.height());
-            }
-
-            // Compress the result into a PNG.
-            ByteArrayOutputStream result = new ByteArrayOutputStream();
-            if (!bitmap.compress(Bitmap.CompressFormat.PNG, 100, result)) return null;
-            bitmap.recycle();
-            return result.toByteArray();
-        } catch (OutOfMemoryError e) {
-            Log.e(TAG, "Out of memory while grabbing window snapshot.", e);
-            return null;
-        }
-    }
-
     private int generateNextRequestCode() {
         int requestCode = REQUEST_CODE_PREFIX + mNextRequestCode;
         mNextRequestCode = (mNextRequestCode + 1) % REQUEST_CODE_RANGE_SIZE;