Make SdchManager per-profile.

chrome/browser/net/sdch_dictionary_fetcher.h

Index: chrome/browser/net/sdch_dictionary_fetcher.h
diff --git a/chrome/browser/net/sdch_dictionary_fetcher.h b/chrome/browser/net/sdch_dictionary_fetcher.h
index 96617438fb90477afbfca891aebd4e64e1d7f51b..e69ec69eab09a5abd22e28a1247836a5cb3f497f 100644
--- a/chrome/browser/net/sdch_dictionary_fetcher.h
+++ b/chrome/browser/net/sdch_dictionary_fetcher.h
@@ -29,13 +29,13 @@ class SdchDictionaryFetcher
       public net::SdchFetcher,
       public base::NonThreadSafe {
  public:
-  explicit SdchDictionaryFetcher(net::URLRequestContextGetter* context);
+  // Consumer must guarantee that the SdchManager pointer outlives
+  // this object.  Usually this is done by making sure the manager

[jar (doing other things), 2014/06/09 23:03:01]

nit: Rather then then passive voice of "Usually this is done..." I think the
comment should indicate how this is achieved in the current implementation.

[Randy Smith (Not in Mondays), 2014/06/10 20:38:41]

Done.

+  // owns this object.
+  SdchDictionaryFetcher(net::SdchManager* manager,
+                        net::URLRequestContextGetter* context);
   virtual ~SdchDictionaryFetcher();
 
-  // Stop fetching dictionaries, and abandon any current URLFetcheer operations
-  // so that the IO thread can be stopped.
-  static void Shutdown();
-
   // Implementation of SdchFetcher class.
   // This method gets the requested dictionary, and then calls back into the
   // SdchManager class with the dictionary's text.
@@ -59,6 +59,8 @@ class SdchDictionaryFetcher
   // completes (either successfully or with failure).
   virtual void OnURLFetchComplete(const net::URLFetcher* source) OVERRIDE;
 
+  net::SdchManager* manager_;

[jar (doing other things), 2014/06/09 23:03:01]

nit: can/should this be const?

[Randy Smith (Not in Mondays), 2014/06/10 20:38:41]

I'm inclined to say "no"; the method that's used on the manager from this class
is AddSdchDictionary(), which to me changes the state of the manager and hence
can't really be consider conceptually const.  But if you have an argument in the
other direction, I'd value hearing it.

[jar (doing other things), 2014/06/11 20:04:43]

To be sure I was clear, I was asking for:
const net::SdchManager* manager_;
and not asking for:
net::SdchManager* const manager_;

const on a pointer is only meant to clarify that the pointed-to-object is always
the same instance, not that the instance state won't change.  This (for example)
means you never have to wonder if the pointer is null.

I use const in cases like this as a matter of course, when I know the pointer
can be established in the constructor, and (at least the pointer would) remain
intact during the life of the object. 

Quoting from the guide:
"Consider making data members const whenever they do not need to be modified
after construction."

In this case, the data member is a pointer (not the instance that is pointed
to).

[Randy Smith (Not in Mondays), 2014/06/11 20:43:37]

Sorry, that was just a braino on my part.  You're quite right.

Having said that, what's required for this to compile is the second form you
quote above, not the first.  That fits with my understanding from Stroustrap as
to how you indicate that the pointer is const rather than the underlying object,
so I went with it.  

Done.

+
   // A queue of URLs that are being used to download dictionaries.
   std::queue<GURL> fetch_queue_;
   // The currently outstanding URL fetch of a dicitonary.