[Presentation API, Android] Implement starting a presentation via CreateRoute()

chrome/android/java/src/org/chromium/chrome/browser/media/router/cast/MediaSource.java

Index: chrome/android/java/src/org/chromium/chrome/browser/media/router/cast/MediaSource.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/media/router/cast/MediaSource.java b/chrome/android/java/src/org/chromium/chrome/browser/media/router/cast/MediaSource.java
index bc9479925a27b335c22c475ee63b8f0a561ba94d..41e22a3a1601809ce94630d039ac1469301f92b3 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/media/router/cast/MediaSource.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/media/router/cast/MediaSource.java
@@ -22,6 +22,7 @@ public class MediaSource {
     private static final String CAST_SOURCE_URN_PARAMETER_SEPARATOR = "/";
     private static final String CAST_SOURCE_URN_APPLICATION_ID_PREFIX = "__castappid__=";
 
+    private final String mSourceUrn;
     private String mApplicationId;
 
     /**
@@ -33,7 +34,7 @@ public class MediaSource {
     public static MediaSource from(String sourceUrn) {
         String applicationId = getCastApplicationId(sourceUrn);
         if (applicationId == null) return null;
-        return new MediaSource(applicationId);
+        return new MediaSource(sourceUrn, applicationId);
     }
 
     /**
@@ -55,7 +56,8 @@ public class MediaSource {
     }
 
     @VisibleForTesting
-    public MediaSource(String applicationId) {
+    public MediaSource(String sourceUrn, String applicationId) {
+        mSourceUrn = sourceUrn;
         mApplicationId = applicationId;
     }
 
@@ -83,4 +85,11 @@ public class MediaSource {
         }
         return null;
     }
+
+    /**
+     * @return the URN identifying the media source
+     */
+    public String getUrn() {
+        return mSourceUrn;
+    }
 }