Initial implementation of Cronet Async API.

components/cronet/android/java/src/org/chromium/net/UrlRequest.java

Index: components/cronet/android/java/src/org/chromium/net/UrlRequest.java
diff --git a/components/cronet/android/java/src/org/chromium/net/UrlRequest.java b/components/cronet/android/java/src/org/chromium/net/UrlRequest.java
index 57a0b439101592235c74d522962acc76dd9dba37..8df71266f519361a9597ba21500bd8f89d763a32 100644
--- a/components/cronet/android/java/src/org/chromium/net/UrlRequest.java
+++ b/components/cronet/android/java/src/org/chromium/net/UrlRequest.java
@@ -9,6 +9,16 @@ package org.chromium.net;
  * Note:  All methods must be called on the Executor passed in during creation.
  */
 public interface UrlRequest {
+    public static final int REQUEST_PRIORITY_IDLE = 0;
+
+    public static final int REQUEST_PRIORITY_LOWEST = 1;
+
+    public static final int REQUEST_PRIORITY_LOW = 2;
+
+    public static final int REQUEST_PRIORITY_MEDIUM = 3;
+
+    public static final int REQUEST_PRIORITY_HIGHEST = 4;
+
     /**
      * More setters go here.  They may only be called before start (Maybe
      * also allow during redirects).  Could optionally instead use arguments
@@ -35,9 +45,8 @@ public interface UrlRequest {
 
     /**
      * Starts the request, all callbacks go to listener.

[mmenke, 2014/11/06 17:31:29]

May only be called once.  May not be called if cancel has been called on the
request.

[mef, 2014/11/06 22:51:47]

Done.

-     * @param listener
      */
-    public void start(UrlRequestListener listener);
+    public void start();
 
     /**
      * Can be called at any time.

[mmenke, 2014/11/06 17:31:29]

+"If the Executor passed to UrlRequest on construction runs tasks on a single
thread, and cancel is called on that thread, no listener methods will be invoked
after cancel is called.  Otherwise, at most one listener method may be made
after cancel has completed."

[mef, 2014/11/06 22:51:47]

Done.