Pass Bitmap's native instance to JNI where feasible

Test: CtsGraphicsTestCases, CtsUiRenderingTestCases,
      CtsRenderscriptTestCases

This is significantly faster than passing the Java object down and then
calling a JNI method to retrieve the pointer. See
https://buganizer.corp.google.com/issues/16656908#comment19

In some cases this changes what used to be native crashes (due to
android::BitmapWrapper:assertValid's LOG_ALWAYS_FATAL_IF) into
NullPointerExceptions (if a caller used a null Bitmap).

In addition:
- Remove unnecessary JNIEnv param from toBitmap(jlong)
- Change instances of toBitmap(JNIEnv*, jobject) to the above
- Replace calls to GraphicsJNI::getSkBitmap() to inline calls to
  toBitmap/getSkBitmap
- make Canvas#nInitRaster @FastNative (FIXME: Could these be
  @CriticalNative?)

Change-Id: I6194097be1b6e6952eba70e1e7052a5a250eed93

graphics/java/android/graphics/BitmapRegionDecoder.java

@@ -196,6 +196,7 @@ public final class BitmapRegionDecoder {
                 throw new IllegalArgumentException("rectangle is outside the image");
             return nativeDecodeRegion(mNativeBitmapRegionDecoder, rect.left, rect.top,
                     rect.right - rect.left, rect.bottom - rect.top, options,
+                    BitmapFactory.Options.nativeInBitmap(options),
                     BitmapFactory.Options.nativeColorSpace(options));
         }
     }
@@ -266,7 +267,8 @@ public final class BitmapRegionDecoder {
 
     private static native Bitmap nativeDecodeRegion(long lbm,
             int start_x, int start_y, int width, int height,
-            BitmapFactory.Options options, long colorSpaceHandle);
+            BitmapFactory.Options options, long inBitmapHandle,
+            long colorSpaceHandle);
     private static native int nativeGetWidth(long lbm);
     private static native int nativeGetHeight(long lbm);
     private static native void nativeClean(long lbm);