Gets presentation ID from route ID upon route creation, and overrides previous presentation ID with…

chrome/browser/media/router/media_route.cc

Index: chrome/browser/media/router/media_route.cc
diff --git a/chrome/browser/media/router/media_route.cc b/chrome/browser/media/router/media_route.cc
index 0aa126f3a2177637b22291c92b07b0cc5fae3461..1279dd163c0883b2f67d5045ce8aa2aaaeb7d676 100644
--- a/chrome/browser/media/router/media_route.cc
+++ b/chrome/browser/media/router/media_route.cc
@@ -7,6 +7,10 @@
 #include "base/logging.h"
 #include "chrome/browser/media/router/media_source.h"
 
+namespace {
+const char kRouteUrnPrefix[] = "urn:x-org.chromium:media:route:";
+}
+
 namespace media_router {
 
 MediaRoute::MediaRoute(const MediaRoute::Id& media_route_id,
@@ -29,4 +33,33 @@ bool MediaRoute::Equals(const MediaRoute& other) const {
   return media_route_id_ == other.media_route_id_;
 }
 
+std::pair<std::string, std::string> GetPresentationIdAndUrl(
+    const MediaRoute::Id& id) {
+  if (id.find(kRouteUrnPrefix) != 0) {
+    LOG(ERROR) << "Invalid media route ID. Expecting prefix "
+               << kRouteUrnPrefix;
+    return std::make_pair(std::string(), std::string());
+  }
+  size_t prefix_len = strlen(kRouteUrnPrefix);
+  size_t first_delim = id.find("/");
+  if (first_delim == std::string::npos || first_delim == prefix_len) {
+    LOG(ERROR) << "Invalid media route ID. Expecting presentation ID.";
+    return std::make_pair(std::string(), std::string());
+  }
+
+  std::string presentation_id = id.substr(prefix_len, first_delim - prefix_len);
+  size_t second_delim = id.find("/", first_delim + 1);
+  if (second_delim == std::string::npos || second_delim == first_delim + 1) {
+    LOG(ERROR) << "Invalid media route ID. Expecting sink.";
+    return std::make_pair(std::string(), std::string());
+  }
+
+  if (second_delim == id.size() - 1) {
+    LOG(ERROR) << "Invalid media route ID. Expecting source.";
+    return std::make_pair(std::string(), std::string());
+  }
+  std::string source = id.substr(second_delim + 1);
+  return std::make_pair(presentation_id, source);
+}
+
 }  // namespace media_router