Add extra data to BrowserContext so that content layer and other embedders can stash data with it t…

content/public/browser/browser_context.h

Index: content/public/browser/browser_context.h
===================================================================
--- content/public/browser/browser_context.h	(revision 121897)
+++ content/public/browser/browser_context.h	(working copy)
@@ -6,7 +6,10 @@
 #define CONTENT_PUBLIC_BROWSER_BROWSER_CONTEXT_H_
 #pragma once
 
+#include <map>
+
 #include "base/hash_tables.h"
+#include "base/memory/linked_ptr.h"
 #include "content/common/content_export.h"
 
 namespace fileapi {
@@ -42,6 +45,19 @@
 // It lives on the UI thread.
 class CONTENT_EXPORT BrowserContext {
  public:
+  // Derive from this class and add your own data members to associate extra
+  // information with a BrowserContext. Use GetUserData(key) and SetUserData()
+  class UserData {

[darin (slow to review), 2012/02/15 00:54:42]

Are you sure you want a map?  It seems like you could get by permitting only one
UserData per BrowserContext.

Also, I wonder if it would be useful to define a class named
base::SupportsUserData that URLRequest and BrowserContext could each derive from
(assuming we wanted to keep the map).  Interesting idea?

[jam, 2012/02/15 01:01:17]

I was thinking that each object that hangs off BrowserContext could have its own
object.
if we only have one, we probably don't want to expose this to embedders then?
i like this, it'll probably make other code cleaner too.

+   public:
+    virtual ~UserData() {}
+  };
+
+  // The user data allows content and the embedder to associate data with this
+  // BrowserContet. Multiple user data values can be stored under different
+  // keys. This object will TAKE OWNERSHIP of the given data pointer.
+  UserData* GetUserData(const void* key) const;
+  void SetUserData(const void* key, UserData* data);
+
   virtual ~BrowserContext();
 
   // Returns the path of the directory where this context's data is stored.
@@ -97,6 +113,10 @@
   virtual ChromeBlobStorageContext* GetBlobStorageContext() = 0;
   virtual ChromeAppCacheService* GetAppCacheService() = 0;
   virtual fileapi::FileSystemContext* GetFileSystemContext() = 0;
+
+ private:
+  typedef std::map<const void*, linked_ptr<UserData> > UserDataMap;
+  UserDataMap user_data_;
 };
 
 }  // namespace content