Implement the skeleton of an android content shell.

base/android/jni_helper.cc

+// Copyright (c) 2012 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.
+
+#include "base/android/jni_helper.h"
+
+#include "base/android/jni_android.h"
+#include "base/logging.h"
+
+using base::android::AttachCurrentThread;
+
+JavaObjectWeakGlobalRef::JavaObjectWeakGlobalRef(JNIEnv* env, jobject obj)
+    : obj_(env->NewWeakGlobalRef(obj)) {
+  DCHECK(obj_);
+}
+
+JavaObjectWeakGlobalRef::~JavaObjectWeakGlobalRef() {
+  DCHECK(obj_);
+  AttachCurrentThread()->DeleteWeakGlobalRef(obj_);
+}
+
+base::android::ScopedJavaLocalRef<jobject>
+    JavaObjectWeakGlobalRef::get(JNIEnv* env) const {
+  return GetRealObject(env, obj_);
+}
+
+base::android::ScopedJavaLocalRef<jobject> GetRealObject(
+    JNIEnv* env, jobject obj) {
+  jobject real = env->NewLocalRef(obj);
+  if (!real)
+    DLOG(ERROR) << "The real object has been deleted!";
+  return base::android::ScopedJavaLocalRef<jobject>(env, real);
+}