A bunch of remaining parts of extension content verification (Reland)

extensions/browser/content_hash_fetcher.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 EXTENSIONS_BROWSER_CONTENT_HASH_FETCHER_H_
 #define EXTENSIONS_BROWSER_CONTENT_HASH_FETCHER_H_
 
+#include "base/memory/weak_ptr.h"
 #include "base/scoped_observer.h"
 #include "extensions/browser/content_verifier_delegate.h"
 #include "extensions/browser/extension_registry_observer.h"
 #include "extensions/common/extension.h"
 
 namespace content {
 class BrowserContext;
 }
 
 namespace extensions {
 
 class ExtensionRegistry;
+class ContentHashFetcherJob;
 
 // This class is responsible for getting signed expected hashes for use in
 // extension content verification. As extensions are loaded it will fetch and
 // parse/validate/cache this data as needed, including calculating expected
 // hashes for each block of each file within an extension. (These unsigned leaf
 // node block level hashes will always be checked at time of use use to make
 // sure they match the signed treehash root hash).
 class ContentHashFetcher : public ExtensionRegistryObserver {
  public:
   // The consumer of this class needs to ensure that context and delegate
@@ skipping 11 matching lines @@
 
   // ExtensionRegistryObserver interface
   virtual void OnExtensionLoaded(content::BrowserContext* browser_context,
                                  const Extension* extension) OVERRIDE;
   virtual void OnExtensionUnloaded(
       content::BrowserContext* browser_context,
       const Extension* extension,
       UnloadedExtensionInfo::Reason reason) OVERRIDE;
 
  private:
+  // Callback for when a job getting content hashes has completed.
+  void JobFinished(ContentHashFetcherJob* job);
+
   content::BrowserContext* context_;
   ContentVerifierDelegate* delegate_;
 
+  // We keep around pointers to in-progress jobs, both so we can avoid
+  // scheduling duplicate work if fetching is already in progress, and so that
+  // we can cancel in-progress work at shutdown time.
+  typedef std::pair<ExtensionId, std::string> IdAndVersion;
+  typedef std::map<IdAndVersion, scoped_refptr<ContentHashFetcherJob> > JobMap;
+  JobMap jobs_;
+
   // For observing the ExtensionRegistry.
   ScopedObserver<ExtensionRegistry, ExtensionRegistryObserver> observer_;
 
+  // Used for binding callbacks passed to jobs.
+  base::WeakPtrFactory<ContentHashFetcher> weak_ptr_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(ContentHashFetcher);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_CONTENT_HASH_FETCHER_H_