Move some content url constants to /url.

chrome/browser/history/in_memory_url_index.cc

Index: chrome/browser/history/in_memory_url_index.cc
diff --git a/chrome/browser/history/in_memory_url_index.cc b/chrome/browser/history/in_memory_url_index.cc
index 21797d7f280dbef37fa514ab0b59ab2bec381e5c..db553a0d00f38bfe483311e8d9a85a09871ee472 100644
--- a/chrome/browser/history/in_memory_url_index.cc
+++ b/chrome/browser/history/in_memory_url_index.cc
@@ -40,11 +40,11 @@ void InitializeSchemeWhitelist(std::set<std::string>* whitelist) {
     return;  // Nothing to do, already initialized.
   whitelist->insert(std::string(content::kAboutScheme));
   whitelist->insert(std::string(content::kChromeUIScheme));
-  whitelist->insert(std::string(content::kFileScheme));
-  whitelist->insert(std::string(content::kFtpScheme));
+  whitelist->insert(std::string(url::kFileScheme));
+  whitelist->insert(std::string(url::kFtpScheme));
   whitelist->insert(std::string(url::kHttpScheme));
   whitelist->insert(std::string(url::kHttpsScheme));
-  whitelist->insert(std::string(content::kMailToScheme));
+  whitelist->insert(std::string(url::kMailToScheme));
 }
 
 // Restore/SaveCacheObserver ---------------------------------------------------