Add Bitmap#getHardwareBuffer

Bug: 148155907
Bug: 135299581
Test: TODO

Hidden for now. We'd like to make it an SDK API eventually
(b/148155907).

Internal code is currently calling createGraphicBufferHandle. This is
not something we plan to expose from the UI rendering module, so add a
method to get a HardwareBuffer instead. This is something we were
already planning to add. It seems that clients of
createGraphicBufferHandle really wanted a Parcelable to pass the
HARDWARE Bitmap to another thread. This should satisfy that use case.

Change-Id: Id701f7c7eab37830cd7d2cdb929cbe6ba4eca119

graphics/java/android/graphics/Bitmap.java

@@ -2243,6 +2243,19 @@ public final class Bitmap implements Parcelable {
         return nativeCreateGraphicBufferHandle(mNativePtr);
     }
 
+    /**
+     * @return {@link HardwareBuffer} which is internally used by hardware bitmap
+     *
+     * Note: the HardwareBuffer does *not* have an associated {@link ColorSpace}.
+     * To render this object the same as its rendered with this Bitmap, you
+     * should also call {@link getColorSpace}.
+     *
+     * @hide
+     */
+    public HardwareBuffer getHardwareBuffer() {
+        return nativeGetHardwareBuffer(mNativePtr);
+    }
+
     //////////// native methods
 
     private static native Bitmap nativeCreate(int[] colors, int offset,
@@ -2308,6 +2321,7 @@ public final class Bitmap implements Parcelable {
     private static native Bitmap nativeWrapHardwareBufferBitmap(HardwareBuffer buffer,
                                                                 long nativeColorSpace);
     private static native GraphicBuffer nativeCreateGraphicBufferHandle(long nativeBitmap);
+    private static native HardwareBuffer nativeGetHardwareBuffer(long nativeBitmap);
     private static native ColorSpace nativeComputeColorSpace(long nativePtr);
     private static native void nativeSetColorSpace(long nativePtr, long nativeColorSpace);
     private static native boolean nativeIsSRGB(long nativePtr);