Documents what ApplicationManager::Delegate do

mojo/shell/application_manager/application_manager.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef SHELL_APPLICATION_MANAGER_APPLICATION_MANAGER_H_
 #define SHELL_APPLICATION_MANAGER_APPLICATION_MANAGER_H_
 
 #include <map>
 
 #include "base/macros.h"
@@ skipping 18 matching lines @@
 namespace mojo {
 namespace shell {
 
 class Fetcher;
 class ShellImpl;
 
 class ApplicationManager {
  public:
   class Delegate {
    public:
-    virtual ~Delegate();
-    virtual GURL ResolveURL(const GURL& url);
-    virtual GURL ResolveMappings(const GURL& url);
+    // Gives the delegate a chance to apply any mappings for the specified url.
+    // This should not resolve 'mojo' urls, that is done by ResolveMojoURL().
+    virtual GURL ResolveMappings(const GURL& url) = 0;
+
+    // Used to map a url with the scheme 'mojo' to the appropriate url. Return
+    // |url| if the scheme is not 'mojo'.
+    virtual GURL ResolveMojoURL(const GURL& url) = 0;
+
+   protected:
+    virtual ~Delegate() {}
   };
 
   // API for testing.
   class TestAPI {
    public:
     explicit TestAPI(ApplicationManager* manager);
     ~TestAPI();
 
     // Returns true if the shared instance has been created.
     static bool HasCreatedInstance();
@@ skipping 164 matching lines @@
   bool disable_cache_;
   base::WeakPtrFactory<ApplicationManager> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ApplicationManager);
 };
 
 }  // namespace shell
 }  // namespace mojo
 
 #endif  // SHELL_APPLICATION_MANAGER_APPLICATION_MANAGER_H_