Update api, add gcm basics

extern/GmsApi

@@ -1 +1 @@
-Subproject commit c0c4a78eab3064cdd7545cb7fcdddfe93ca1674d
+Subproject commit c43facae3dba6fcf4139c6a36e3a6f364d6db057

play-services-base/src/main/java/com/google/android/gms/gcm/GoogleCloudMessaging.java

@@ -0,0 +1,115 @@
+/*
+ * Copyright 2013-2015 µg Project Team
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.android.gms.gcm;
+
+import android.content.Context;
+import android.content.Intent;
+import android.os.Bundle;
+
+import java.io.IOException;
+
+public class GoogleCloudMessaging {
+
+    /**
+     * The GCM {@link #register(String...)} and {@link #unregister()} methods are blocking. You
+     * should not run them in the main thread or in broadcast receivers.
+     */
+    public static final String ERROR_MAIN_THREAD = "MAIN_THREAD";
+
+    /**
+     * The device can't read the response, or there was a 500/503 from the server that can be
+     * retried later. The application should use exponential back off and retry.
+     */
+    public static final String ERROR_SERVICE_NOT_AVAILABLE = "SERVICE_NOT_AVAILABLE";
+
+    /**
+     * Returned by {@link #getMessageType(Intent)} to indicate that the server deleted some
+     * pending messages because they were collapsible.
+     */
+    public static final String MESSAGE_TYPE_DELETED = "deleted_messages";
+
+    /**
+     * Returned by {@link #getMessageType(Intent)} to indicate a regular message.
+     */
+    public static final String MESSAGE_TYPE_MESSAGE = "gcm";
+
+    /**
+     * Returned by {@link #getMessageType(Intent)} to indicate a send error. The intent includes
+     * the message ID of the message and an error code.
+     */
+    public static final String MESSAGE_TYPE_SEND_ERROR = "send_error";
+
+    /**
+     * Return the singleton instance of GCM.
+     */
+    public static synchronized GoogleCloudMessaging getInstance(Context context) {
+        return null;
+    }
+
+    /**
+     * Must be called when your application is done using GCM, to release internal resources.
+     */
+    public void close() {
+
+    }
+
+    /**
+     * Return the message type from an intent passed into a client app's broadcast receiver.
+     * There are two general categories of messages passed from the server: regular GCM messages,
+     * and special GCM status messages. The possible types are:
+     * <ul>
+     * <li>{@link #MESSAGE_TYPE_MESSAGE}—regular message from your server.</li>
+     * <li>{@link #MESSAGE_TYPE_DELETED}—special status message indicating that some messages have been collapsed by GCM.</li>
+     * <li>{@link #MESSAGE_TYPE_SEND_ERROR}—special status message indicating that there were errors sending one of the messages.</li>
+     * </ul>
+     * You can use this method to filter based on message type. Since it is likely that GCM will
+     * be extended in the future with new message types, just ignore any message types you're not
+     * interested in, or that you don't recognize.
+     *
+     * @param intent
+     * @return
+     */
+    public String getMessageType(Intent intent) {
+        return null;
+    }
+
+    public String register(String... senderIds) {
+        return null;
+    }
+
+    public void send(String to, String msgId, long timeToLive, Bundle data) {
+
+    }
+
+    public void send(String to, String msgId, Bundle data) {
+
+    }
+
+    /**
+     * Unregister the application. Calling unregister() stops any messages from the server.
+     * This is a blocking call—you shouldn't call it from the UI thread.
+     * You should rarely (if ever) need to call this method. Not only is it expensive in terms of
+     * resources, but it invalidates your registration ID, which you should never change
+     * unnecessarily. A better approach is to simply have your server stop sending messages.
+     * Only use unregister if you want to change your sender ID.
+     *
+     * @throws IOException if we can't connect to server to unregister.
+     */
+    public void unregister() throws IOException {
+
+    }
+}