[Media Router] Convert MediaRouter to use GURL for presentation URLs.

chrome/browser/media/router/media_source_helper.h

Index: chrome/browser/media/router/media_source_helper.h
diff --git a/chrome/browser/media/router/media_source_helper.h b/chrome/browser/media/router/media_source_helper.h
index e6c0c51b5c9911e2e514accd77fad1359fdacd7e..f9356cd1073a4ca5d04d19b1fb189f407d921159 100644
--- a/chrome/browser/media/router/media_source_helper.h
+++ b/chrome/browser/media/router/media_source_helper.h
@@ -9,6 +9,8 @@
 
 #include "chrome/browser/media/router/media_source.h"
 
+class GURL;
+
 namespace content {
 class WebContents;
 }
@@ -20,8 +22,7 @@ namespace media_router {
 MediaSource MediaSourceForTab(int tab_id);
 MediaSource MediaSourceForTabContentRemoting(content::WebContents* contents);
 MediaSource MediaSourceForDesktop();
-MediaSource MediaSourceForCastApp(const std::string& app_id);
-MediaSource MediaSourceForPresentationUrl(const std::string& presentation_url);
+MediaSource MediaSourceForPresentationUrl(const GURL& presentation_url);
 
 // Returns true if |source| outputs its content via mirroring.
 bool IsDesktopMirroringMediaSource(const MediaSource& source);
@@ -36,12 +37,8 @@ int TabIdFromMediaSource(const MediaSource& source);
 // Does not deeper protocol-level syntax checks.
 bool IsValidMediaSource(const MediaSource& source);
 
-// Extracts the presentation URL from |source|.
-// If |source| is invalid, an empty string is returned.
-std::string PresentationUrlFromMediaSource(const MediaSource& source);
-
-// Returns true if |source| is a valid presentation URL.
-bool IsValidPresentationUrl(const std::string& url);
+// Returns true if |url| is a valid presentation URL.
+bool IsValidPresentationUrl(const GURL& url);
 
 }  // namespace media_router