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

content/public/browser/presentation_session.h

Index: content/public/browser/presentation_session.h
diff --git a/content/public/browser/presentation_session.h b/content/public/browser/presentation_session.h
index 8662f3049205d6f65fb08911eae31f29187c7020..8e5eb54676d349921ea4872aa2c93fd359a0a9dd 100644
--- a/content/public/browser/presentation_session.h
+++ b/content/public/browser/presentation_session.h
@@ -8,6 +8,7 @@
 #include <string>
 
 #include "content/common/content_export.h"
+#include "url/gurl.h"
 
 namespace content {
 
@@ -30,11 +31,11 @@ enum PresentationConnectionCloseReason {
 // Represents a presentation session that has been established via either
 // browser actions or Presentation API.
 struct CONTENT_EXPORT PresentationSessionInfo {
-  PresentationSessionInfo(const std::string& presentation_url,
+  PresentationSessionInfo(const GURL& presentation_url,
                           const std::string& presentation_id);
   ~PresentationSessionInfo();
 
-  const std::string presentation_url;
+  const GURL presentation_url;
   const std::string presentation_id;
 };