Make SdchManager per-profile.

chrome/browser/net/sdch_dictionary_fetcher.h

 // Copyright (c) 2012 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.
 
 // Support modularity by calling to load a new SDCH filter dictionary.
 // Note that this sort of calling can't be done in the /net directory, as it has
 // no concept of the HTTP cache (which is only visible at the browser level).
 
 #ifndef CHROME_BROWSER_NET_SDCH_DICTIONARY_FETCHER_H_
 #define CHROME_BROWSER_NET_SDCH_DICTIONARY_FETCHER_H_
@@ skipping 11 matching lines @@
 namespace net {
 class URLFetcher;
 class URLRequestContextGetter;
 }  // namespace net
 
 class SdchDictionaryFetcher
     : public net::URLFetcherDelegate,
       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
+  // 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();

[jar (doing other things), 2014/05/27 17:53:09]

Given that the dictionary fetch is very async... I would expect that you'll need
some shutdown call to abandon such a pending fetch.

[Randy Smith (Not in Mondays), 2014/06/04 22:04:52]

I believe what I currently have is equivalent to the old global code with regard
to shutdown; do you disagree with that claim, or do you think that I need to add
something to shutdown pending fetches that wasn't in the original code?

Support for above statements: In the original code,
BrowserProcessImpl::StartTearDown called SdchDictionaryFetcher::Shutdown(),
which called SdchManager::Shutdown(), which reset the SdchDictionaryFetcher
scoped_ptr<> to null, which triggered the SdchDictionaryFetcher() destructor. 
In the current code, when the ProfileImplIOData is torn down (which I think is
before BrowserProcessImpl::StartTearDown, as it's per-profile), that results in
SdchManager destruction, which will result in SdchFetcher scoped_ptr<> nulling,
which will result in SdchDictionaryFetcher destruction.

I believe that SdchDictionaryFetcher destruction results in cancellation, since
it results in URLFetcher destruction, which results in calling
URLFetcherCore::Stop().

-
   // Implementation of SdchFetcher class.
   // This method gets the requested dictionary, and then calls back into the
   // SdchManager class with the dictionary's text.
   virtual void Schedule(const GURL& dictionary_url) OVERRIDE;
 
  private:
   // Delay in ms between Schedule and actual download.
   // This leaves the URL in a queue, which is de-duped, so that there is less
   // chance we'll try to load the same URL multiple times when a pile of
   // page subresources (or tabs opened in parallel) all suggest the dictionary.
   static const int kMsDelayFromRequestTillDownload = 100;
 
   // Ensure the download after the above delay.
   void ScheduleDelayedRun();
 
   // Make sure we're processing (or waiting for) the the arrival of the next URL
   // in the  |fetch_queue_|.
   void StartFetching();
 
   // Implementation of net::URLFetcherDelegate. Called after transmission
   // completes (either successfully or with failure).
   virtual void OnURLFetchComplete(const net::URLFetcher* source) OVERRIDE;
 
+  net::SdchManager* manager_;
+
   // A queue of URLs that are being used to download dictionaries.
   std::queue<GURL> fetch_queue_;
   // The currently outstanding URL fetch of a dicitonary.
   // If this is null, then there is no outstanding request.
   scoped_ptr<net::URLFetcher> current_fetch_;
 
   // Always spread out the dictionary fetches, so that they don't steal
   // bandwidth from the actual page load.  Create delayed tasks to spread out
   // the download.
   base::WeakPtrFactory<SdchDictionaryFetcher> weak_factory_;
@@ skipping 15 matching lines @@
   std::set<GURL> attempted_load_;
 
   // Store the system_url_request_context_getter to use it when we start
   // fetching.
   scoped_refptr<net::URLRequestContextGetter> context_;
 
   DISALLOW_COPY_AND_ASSIGN(SdchDictionaryFetcher);
 };
 
 #endif  // CHROME_BROWSER_NET_SDCH_DICTIONARY_FETCHER_H_