[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..4b92063e84ef06af806326a1cf37d0c9b65087c9 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;
 }
@@ -21,7 +23,7 @@ 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 +38,8 @@ 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