Clean up base::android::Init/GetApplicationContext()

base/android/jni_android.h

 // Copyright (c) 2011 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 BASE_ANDROID_JNI_ANDROID_H_
 #define BASE_ANDROID_JNI_ANDROID_H_
 
 #include <jni.h>
 #include <sys/types.h>
 
+#include "base/android/scoped_java_ref.h"
+
 namespace base {
 namespace android {
 
 // Attach the current thread to the VM (if necessary) and return the JNIEnv*.
 JNIEnv* AttachCurrentThread();
 
 // Detach the current thread from VM if it is attached.
 void DetachFromVM();
 
 // Initializes the global JVM. It is not necessarily called before
 // InitApplicationContext().
 void InitVM(JavaVM* vm);
 
-// Initializes the global application context object. The |context| should be
-// the global reference of application context object.  It is not necessarily
-// called after InitVM().
+// Initializes the global application context object. The |context| can be any
+// valid reference to the application context. Internally holds a global ref to
+// the context. InitVM and InitApplicationContext maybe called in either order.
 // TODO: We might combine InitVM() and InitApplicationContext() into one method.
-void InitApplicationContext(jobject context);
+void InitApplicationContext(const JavaRef<jobject>& context);
 
-// Returns the application context assigned by InitApplicationContext().
+// Gets a global ref to the application context set with
+// InitApplicationContext(). Ownership is retained by the function - the caller
+// must NOT release it.
 jobject GetApplicationContext();
 
 // Gets the method ID from the class name. Clears the pending Java exception
 // and returns NULL if the method is not found. Caches results. Note that
 // GetMethodID() below avoids a class lookup, but does not cache results.
 // Strings passed to this function are held in the cache and MUST remain valid
 // beyond the duration of all future calls to this function, across all
 // threads. In practice, this means that the function should only be used with
 // string constants.
 jmethodID GetMethodIDFromClassName(JNIEnv* env,
@@ skipping 23 matching lines @@
                     const char* jni_signature);
 
 // Returns true if an exception is pending in the provided JNIEnv*. If an
 // exception is pending, this function prints and then clears it.
 bool CheckException(JNIEnv* env);
 
 }  // namespace android
 }  // namespace base
 
 #endif  // BASE_ANDROID_JNI_ANDROID_H_