Pass method parameters as JavaParamRef in android_webview.

android_webview/native/aw_picture.h

 // Copyright 2013 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.
 
 #ifndef ANDROID_WEBVIEW_NATIVE_AW_PICTURE_H_
 #define ANDROID_WEBVIEW_NATIVE_AW_PICTURE_H_
 
 #include <jni.h>
 
 #include "base/android/jni_weak_ref.h"
 #include "base/android/scoped_java_ref.h"
 #include "base/memory/scoped_ptr.h"
 #include "content/public/browser/web_contents_observer.h"
 #include "skia/ext/refptr.h"
 
 class SkPicture;
 
 namespace android_webview {
 
 class AwPicture {
  public:
   AwPicture(skia::RefPtr<SkPicture> picture);
   ~AwPicture();
 
   // Methods called from Java.
-  void Destroy(JNIEnv* env, jobject obj);
-  jint GetWidth(JNIEnv* env, jobject obj);
-  jint GetHeight(JNIEnv* env, jobject obj);
-  void Draw(JNIEnv* env, jobject obj, jobject canvas);
+  void Destroy(JNIEnv* env, const base::android::JavaParamRef<jobject>& obj);
+  jint GetWidth(JNIEnv* env, const base::android::JavaParamRef<jobject>& obj);
+  jint GetHeight(JNIEnv* env, const base::android::JavaParamRef<jobject>& obj);
+  void Draw(JNIEnv* env,
+            const base::android::JavaParamRef<jobject>& obj,
+            const base::android::JavaParamRef<jobject>& canvas);
 
  private:
   skia::RefPtr<SkPicture> picture_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(AwPicture);
 };
 
 bool RegisterAwPicture(JNIEnv* env);
 
 }  // android_webview
 
 #endif  // ANDROID_WEBVIEW_NATIVE_AW_PICTURE_