hidden api sameAs() to compare the pixels of 2 bitmaps for equality

graphics/java/android/graphics/Bitmap.java

@@ -971,6 +971,19 @@ public final class Bitmap implements Parcelable {
         return bm;
     }
 
+    /**
+     *  Given another bitmap, return true if it has the same dimensions, config,
+     *  and pixel data as this bitmap. If any of those differ, return false.
+     *  If other is null, return false.
+     *
+     * @hide (just needed internally right now)
+     */
+    public boolean sameAs(Bitmap other) {
+        return this == other ||
+              (other != null &&
+               nativeSameAs(mNativeBitmap, other.mNativeBitmap));
+    }
+
     /**
      * Rebuilds any caches associated with the bitmap that are used for
      * drawing it. In the case of purgeable bitmaps, this call will attempt to
@@ -1042,6 +1055,7 @@ public final class Bitmap implements Parcelable {
 
     private static native void nativePrepareToDraw(int nativeBitmap);
     private static native void nativeSetHasAlpha(int nBitmap, boolean hasAlpha);
+    private static native boolean nativeSameAs(int nb0, int nb1);
 
     /* package */ final int ni() {
         return mNativeBitmap;