Created a DownloadManager interface, for use in unit tests..

content/browser/download/download_manager.h

Index: content/browser/download/download_manager.h
diff --git a/content/browser/download/download_manager.h b/content/browser/download/download_manager.h
index cf8d2db4a181143d753237d84207361f1c49f600..e840767f0cec83b5619bdfc00bebe7065282b718 100644
--- a/content/browser/download/download_manager.h
+++ b/content/browser/download/download_manager.h
@@ -67,18 +67,14 @@ class BrowserContext;
 class DownloadManagerDelegate;
 }
 
-// Browser's download manager: manages all downloads and destination view.
 class CONTENT_EXPORT DownloadManager
     : public base::RefCountedThreadSafe<
-          DownloadManager, content::BrowserThread::DeleteOnUIThread>,
-      public DownloadStatusUpdaterDelegate {
+          DownloadManager, content::BrowserThread::DeleteOnUIThread> {
  public:
-  DownloadManager(content::DownloadManagerDelegate* delegate,
-                  DownloadIdFactory* id_factory,
-                  DownloadStatusUpdater* status_updater);
+  virtual ~DownloadManager() {}
 
   // Shutdown the download manager. Must be called before destruction.
-  void Shutdown();
+  virtual void Shutdown() = 0;
 
   // Interface to implement for observers that wish to be informed of changes
   // to the DownloadManager's collection of downloads.
@@ -104,187 +100,296 @@ class CONTENT_EXPORT DownloadManager
   typedef std::vector<DownloadItem*> DownloadVector;
 
   // Return all temporary downloads that reside in the specified directory.
-  void GetTemporaryDownloads(const FilePath& dir_path, DownloadVector* result);
+  virtual void GetTemporaryDownloads(const FilePath& dir_path,
+                                     DownloadVector* result) = 0;
 
   // Return all non-temporary downloads in the specified directory that are
   // are in progress or have completed.
-  void GetAllDownloads(const FilePath& dir_path, DownloadVector* result);
+  virtual void GetAllDownloads(const FilePath& dir_path,
+                               DownloadVector* result) = 0;
 
   // Returns all non-temporary downloads matching |query|. Empty query matches
   // everything.
-  void SearchDownloads(const string16& query, DownloadVector* result);
+  virtual void SearchDownloads(const string16& query,
+                               DownloadVector* result) = 0;
 
   // Returns true if initialized properly.
-  bool Init(content::BrowserContext* browser_context);
+  virtual bool Init(content::BrowserContext* browser_context) = 0;
 
   // Notifications sent from the download thread to the UI thread
-  void StartDownload(int32 id);
-  void UpdateDownload(int32 download_id, int64 size);
+  virtual void StartDownload(int32 id) = 0;
+  virtual void UpdateDownload(int32 download_id, int64 size) = 0;
 
   // |download_id| is the ID of the download.
   // |size| is the number of bytes that have been downloaded.
   // |hash| is sha256 hash for the downloaded file. It is empty when the hash
   // is not available.
-  void OnResponseCompleted(int32 download_id, int64 size,
-                           const std::string& hash);
+  virtual void OnResponseCompleted(int32 download_id, int64 size,
+                           const std::string& hash) = 0;
 
   // Offthread target for cancelling a particular download.  Will be a no-op
   // if the download has already been cancelled.
-  void CancelDownload(int32 download_id);
+  virtual void CancelDownload(int32 download_id) = 0;
 
   // Called when there is an error in the download.
   // |download_id| is the ID of the download.
   // |size| is the number of bytes that are currently downloaded.
   // |reason| is a download interrupt reason code.
-  void OnDownloadInterrupted(int32 download_id, int64 size,
-                             InterruptReason reason);
+  virtual void OnDownloadInterrupted(int32 download_id, int64 size,
+                             InterruptReason reason) = 0;
 
   // Called from DownloadItem to handle the DownloadManager portion of a
   // Cancel; should not be called from other locations.
-  void DownloadCancelledInternal(DownloadItem* download);
+  virtual void DownloadCancelledInternal(DownloadItem* download) = 0;
 
   // Called from a view when a user clicks a UI button or link.
-  void RemoveDownload(int64 download_handle);
+  virtual void RemoveDownload(int64 download_handle) = 0;
 
   // Determine if the download is ready for completion, i.e. has had
   // all data saved, and completed the filename determination and
   // history insertion.
-  bool IsDownloadReadyForCompletion(DownloadItem* download);
+  virtual bool IsDownloadReadyForCompletion(DownloadItem* download) = 0;
 
   // If all pre-requisites have been met, complete download processing, i.e.
   // do internal cleanup, file rename, and potentially auto-open.
   // (Dangerous downloads still may block on user acceptance after this
   // point.)
-  void MaybeCompleteDownload(DownloadItem* download);
+  virtual void MaybeCompleteDownload(DownloadItem* download) = 0;
 
   // Called when the download is renamed to its final name.
   // |uniquifier| is a number used to make unique names for the file.  It is
   // only valid for the DANGEROUS_BUT_VALIDATED state of the download item.
-  void OnDownloadRenamedToFinalName(int download_id,
+  virtual void OnDownloadRenamedToFinalName(int download_id,
                                     const FilePath& full_path,
-                                    int uniquifier);
+                                    int uniquifier) = 0;
 
   // Remove downloads after remove_begin (inclusive) and before remove_end
   // (exclusive). You may pass in null Time values to do an unbounded delete
   // in either direction.
-  int RemoveDownloadsBetween(const base::Time remove_begin,
-                             const base::Time remove_end);
+  virtual int RemoveDownloadsBetween(const base::Time remove_begin,
+                             const base::Time remove_end) = 0;
 
   // Remove downloads will delete all downloads that have a timestamp that is
   // the same or more recent than |remove_begin|. The number of downloads
   // deleted is returned back to the caller.
-  int RemoveDownloads(const base::Time remove_begin);
+  virtual int RemoveDownloads(const base::Time remove_begin) = 0;
 
   // Remove all downloads will delete all downloads. The number of downloads
   // deleted is returned back to the caller.
-  int RemoveAllDownloads();
+  virtual int RemoveAllDownloads() = 0;
 
   // Final download manager transition for download: Update the download
   // history and remove the download from |active_downloads_|.
-  void DownloadCompleted(int32 download_id);
+  virtual void DownloadCompleted(int32 download_id) = 0;
 
   // Download the object at the URL. Used in cases such as "Save Link As..."
-  void DownloadUrl(const GURL& url,
+  virtual void DownloadUrl(const GURL& url,
                    const GURL& referrer,
                    const std::string& referrer_encoding,
-                   TabContents* tab_contents);
+                   TabContents* tab_contents) = 0;
 
   // Download the object at the URL and save it to the specified path. The
   // download is treated as the temporary download and thus will not appear
   // in the download history. Used in cases such as drag and drop.
-  void DownloadUrlToFile(const GURL& url,
+  virtual void DownloadUrlToFile(const GURL& url,
                          const GURL& referrer,
                          const std::string& referrer_encoding,
                          const DownloadSaveInfo& save_info,
-                         TabContents* tab_contents);
+                         TabContents* tab_contents) = 0;
 
   // Allow objects to observe the download creation process.
-  void AddObserver(Observer* observer);
+  virtual void AddObserver(Observer* observer) = 0;
 
   // Remove a download observer from ourself.
-  void RemoveObserver(Observer* observer);
+  virtual void RemoveObserver(Observer* observer) = 0;
 
   // Called by the embedder, after creating the download manager, to let it know
   // about downloads from previous runs of the browser.
-  void OnPersistentStoreQueryComplete(
-      std::vector<DownloadPersistentStoreInfo>* entries);
+  virtual void OnPersistentStoreQueryComplete(
+      std::vector<DownloadPersistentStoreInfo>* entries) = 0;
 
   // Called by the embedder, in response to
   // DownloadManagerDelegate::AddItemToPersistentStore.
-  void OnItemAddedToPersistentStore(int32 download_id, int64 db_handle);
+  virtual void OnItemAddedToPersistentStore(int32 download_id,
+                                            int64 db_handle) = 0;
 
   // Display a new download in the appropriate browser UI.
-  void ShowDownloadInBrowser(DownloadItem* download);
+  virtual void ShowDownloadInBrowser(DownloadItem* download) = 0;
 
   // The number of in progress (including paused) downloads.
-  int in_progress_count() const {
-    return static_cast<int>(in_progress_.size());
-  }
+  virtual int InProgressCount() const = 0;
 
-  content::BrowserContext* browser_context() { return browser_context_; }
+  virtual content::BrowserContext* BrowserContext() = 0;
 
-  FilePath last_download_path() { return last_download_path_; }
+  virtual FilePath LastDownloadPath() = 0;
 
   // Creates the download item.  Must be called on the UI thread.
-  void CreateDownloadItem(DownloadCreateInfo* info,
-                          const DownloadRequestHandle& request_handle);
+  virtual void CreateDownloadItem(DownloadCreateInfo* info,
+                          const DownloadRequestHandle& request_handle) = 0;
 
   // Clears the last download path, used to initialize "save as" dialogs.
-  void ClearLastDownloadPath();
-
-  // Overridden from DownloadStatusUpdaterDelegate:
-  virtual bool IsDownloadProgressKnown() const OVERRIDE;
-  virtual int64 GetInProgressDownloadCount() const OVERRIDE;
-  virtual int64 GetReceivedDownloadBytes() const OVERRIDE;
-  virtual int64 GetTotalDownloadBytes() const OVERRIDE;
+  virtual void ClearLastDownloadPath() = 0;
 
   // Called by the delegate after the save as dialog is closed.
-  void FileSelected(const FilePath& path, void* params);
-  void FileSelectionCanceled(void* params);
+  virtual void FileSelected(const FilePath& path, void* params) = 0;
+  virtual void FileSelectionCanceled(void* params) = 0;
 
   // Called by the delegate if it delayed the download in
   // DownloadManagerDelegate::ShouldStartDownload and now is ready.
-  void RestartDownload(int32 download_id);
+  virtual void RestartDownload(int32 download_id) = 0;
 
   // Mark the download opened in the persistent store.
-  void MarkDownloadOpened(DownloadItem* download);
+  virtual void MarkDownloadOpened(DownloadItem* download) = 0;
 
   // Checks whether downloaded files still exist. Updates state of downloads
   // that refer to removed files. The check runs in the background and may
   // finish asynchronously after this method returns.
-  void CheckForHistoryFilesRemoval();
+  virtual void CheckForHistoryFilesRemoval() = 0;
 
   // Checks whether a downloaded file still exists and updates the file's state
   // if the file is already removed. The check runs in the background and may
   // finish asynchronously after this method returns.
-  void CheckForFileRemoval(DownloadItem* download_item);
+  virtual void CheckForFileRemoval(DownloadItem* download_item) = 0;
 
   // Assert the named download item is on the correct queues
   // in the DownloadManager.  For debugging.
-  void AssertQueueStateConsistent(DownloadItem* download);
+  virtual void AssertQueueStateConsistent(DownloadItem* download) = 0;
 
   // Get the download item from the history map.  Useful after the item has
   // been removed from the active map, or was retrieved from the history DB.
-  DownloadItem* GetDownloadItem(int id);
+  virtual DownloadItem* GetDownloadItem(int id) = 0;
 
   // Called when Save Page download starts. Transfers ownership of |download|
   // to the DownloadManager.
-  void SavePageDownloadStarted(DownloadItem* download);
+  virtual void SavePageDownloadStarted(DownloadItem* download) = 0;
 
   // Called when Save Page download is done.
-  void SavePageDownloadFinished(DownloadItem* download);
+  virtual void SavePageDownloadFinished(DownloadItem* download) = 0;
 
   // Get the download item from the active map.  Useful when the item is not
   // yet in the history map.
-  DownloadItem* GetActiveDownloadItem(int id);
+  virtual DownloadItem* GetActiveDownloadItem(int id) = 0;
 
-  content::DownloadManagerDelegate* delegate() const { return delegate_; }
+  virtual content::DownloadManagerDelegate* delegate() const = 0;
 
   // For testing only.  May be called from tests indirectly (through
   // other for testing only methods).
-  void SetDownloadManagerDelegate(content::DownloadManagerDelegate* delegate);
+  virtual void SetDownloadManagerDelegate(
+      content::DownloadManagerDelegate* delegate) = 0;
+
+  virtual DownloadId GetNextId() = 0;
+
+ protected:
+  // These functions are here for unit tests.
+
+  // Called back after a target path for the file to be downloaded to has been
+  // determined, either automatically based on the suggested file name, or by
+  // the user in a Save As dialog box.
+  virtual void ContinueDownloadWithPath(DownloadItem* download,
+                                        const FilePath& chosen_file) = 0;
+
+  // Retrieves the download from the |download_id|.
+  // Returns NULL if the download is not active.
+  virtual DownloadItem* GetActiveDownload(int32 download_id) = 0;
+
+  virtual void SetFileManager(DownloadFileManager* file_manager) = 0;
+
+private:
+  // For testing.
+  friend class DownloadManagerTest;
+  friend class DownloadTest;
+  friend class MockDownloadManager;
+
+  friend class base::RefCountedThreadSafe<
+      DownloadManager, content::BrowserThread::DeleteOnUIThread>;
+  friend struct content::BrowserThread::DeleteOnThread<
+      content::BrowserThread::UI>;
+  friend class DeleteTask<DownloadManager>;
+};
+
+// Browser's download manager: manages all downloads and destination view.

[Randy Smith (Not in Mondays), 2011/11/08 22:10:51]

I *think* this comment is more appropriate next to the interface class above. 
It's a tricky call, but I think the object that's managing the downloads is more
associated with the interface (and all the comments on the interface) than with
the implementation class.

[ahendrickson, 2011/11/09 17:09:02]

Done.

+class CONTENT_EXPORT DownloadManagerImpl
+    : public DownloadManager,
+      public DownloadStatusUpdaterDelegate {
+ public:
+  DownloadManagerImpl(content::DownloadManagerDelegate* delegate,
+                  DownloadIdFactory* id_factory,
+                  DownloadStatusUpdater* status_updater);
+
+  // DownloadManager functions.
+  virtual void Shutdown() OVERRIDE;
+  virtual void GetTemporaryDownloads(const FilePath& dir_path,
+                                     DownloadVector* result) OVERRIDE;
+  virtual void GetAllDownloads(const FilePath& dir_path,
+                               DownloadVector* result) OVERRIDE;
+  virtual void SearchDownloads(const string16& query,
+                               DownloadVector* result) OVERRIDE;
+  virtual bool Init(content::BrowserContext* browser_context) OVERRIDE;
+  virtual void StartDownload(int32 id) OVERRIDE;
+  virtual void UpdateDownload(int32 download_id, int64 size) OVERRIDE;
+  virtual void OnResponseCompleted(int32 download_id, int64 size,
+                                   const std::string& hash) OVERRIDE;
+  virtual void CancelDownload(int32 download_id) OVERRIDE;
+  virtual void OnDownloadInterrupted(int32 download_id, int64 size,
+                                     InterruptReason reason) OVERRIDE;
+  virtual void DownloadCancelledInternal(DownloadItem* download) OVERRIDE;
+  virtual void RemoveDownload(int64 download_handle) OVERRIDE;
+  virtual bool IsDownloadReadyForCompletion(DownloadItem* download) OVERRIDE;
+  virtual void MaybeCompleteDownload(DownloadItem* download) OVERRIDE;
+  virtual void OnDownloadRenamedToFinalName(int download_id,
+                                            const FilePath& full_path,
+                                            int uniquifier) OVERRIDE;
+  virtual int RemoveDownloadsBetween(const base::Time remove_begin,
+                                     const base::Time remove_end) OVERRIDE;
+  virtual int RemoveDownloads(const base::Time remove_begin) OVERRIDE;
+  virtual int RemoveAllDownloads() OVERRIDE;
+  virtual void DownloadCompleted(int32 download_id) OVERRIDE;
+  virtual void DownloadUrl(const GURL& url,
+                           const GURL& referrer,
+                           const std::string& referrer_encoding,
+                           TabContents* tab_contents) OVERRIDE;
+  virtual void DownloadUrlToFile(const GURL& url,
+                                 const GURL& referrer,
+                                 const std::string& referrer_encoding,
+                                 const DownloadSaveInfo& save_info,
+                                 TabContents* tab_contents) OVERRIDE;
+  virtual void AddObserver(Observer* observer) OVERRIDE;
+  virtual void RemoveObserver(Observer* observer) OVERRIDE;
+  virtual void OnPersistentStoreQueryComplete(
+      std::vector<DownloadPersistentStoreInfo>* entries) OVERRIDE;
+  virtual void OnItemAddedToPersistentStore(int32 download_id,
+                                            int64 db_handle) OVERRIDE;
+  virtual void ShowDownloadInBrowser(DownloadItem* download) OVERRIDE;
+  virtual int InProgressCount() const OVERRIDE;
+  virtual content::BrowserContext* BrowserContext() OVERRIDE;
+  virtual FilePath LastDownloadPath() OVERRIDE;
+  virtual void CreateDownloadItem(
+      DownloadCreateInfo* info,
+      const DownloadRequestHandle& request_handle) OVERRIDE;
+  virtual void ClearLastDownloadPath() OVERRIDE;
+
+  // Overridden from DownloadStatusUpdaterDelegate:
+  virtual bool IsDownloadProgressKnown() const OVERRIDE;
+  virtual int64 GetInProgressDownloadCount() const OVERRIDE;
+  virtual int64 GetReceivedDownloadBytes() const OVERRIDE;
+  virtual int64 GetTotalDownloadBytes() const OVERRIDE;
 
-  DownloadId GetNextId();
+  // More DownloadManager functions.
+  virtual void FileSelected(const FilePath& path, void* params) OVERRIDE;
+  virtual void FileSelectionCanceled(void* params) OVERRIDE;
+  virtual void RestartDownload(int32 download_id) OVERRIDE;
+  virtual void MarkDownloadOpened(DownloadItem* download) OVERRIDE;
+  virtual void CheckForHistoryFilesRemoval() OVERRIDE;
+  virtual void CheckForFileRemoval(DownloadItem* download_item) OVERRIDE;
+  virtual void AssertQueueStateConsistent(DownloadItem* download) OVERRIDE;
+  virtual DownloadItem* GetDownloadItem(int id) OVERRIDE;
+  virtual void SavePageDownloadStarted(DownloadItem* download) OVERRIDE;
+  virtual void SavePageDownloadFinished(DownloadItem* download) OVERRIDE;
+  virtual DownloadItem* GetActiveDownloadItem(int id) OVERRIDE;
+  virtual content::DownloadManagerDelegate* delegate() const OVERRIDE;
+  virtual void SetDownloadManagerDelegate(
+      content::DownloadManagerDelegate* delegate) OVERRIDE;
+  virtual DownloadId GetNextId() OVERRIDE;
 
  private:
   typedef std::set<DownloadItem*> DownloadSet;
@@ -296,12 +401,12 @@ class CONTENT_EXPORT DownloadManager
   friend class MockDownloadManager;
 
   friend class base::RefCountedThreadSafe<
-      DownloadManager, content::BrowserThread::DeleteOnUIThread>;
+      DownloadManagerImpl, content::BrowserThread::DeleteOnUIThread>;
   friend struct content::BrowserThread::DeleteOnThread<
       content::BrowserThread::UI>;
-  friend class DeleteTask<DownloadManager>;
+  friend class DeleteTask<DownloadManagerImpl>;
 
-  virtual ~DownloadManager();
+  virtual ~DownloadManagerImpl();
 
   // Called on the FILE thread to check the existence of a downloaded file.
   void CheckForFileRemovalOnFileThread(int64 db_handle, const FilePath& path);
@@ -314,12 +419,12 @@ class CONTENT_EXPORT DownloadManager
   // Called back after a target path for the file to be downloaded to has been
   // determined, either automatically based on the suggested file name, or by
   // the user in a Save As dialog box.
-  void ContinueDownloadWithPath(DownloadItem* download,
-                                const FilePath& chosen_file);
+  virtual void ContinueDownloadWithPath(DownloadItem* download,
+                                        const FilePath& chosen_file) OVERRIDE;
 
   // Retrieves the download from the |download_id|.
   // Returns NULL if the download is not active.
-  DownloadItem* GetActiveDownload(int32 download_id);
+  virtual DownloadItem* GetActiveDownload(int32 download_id) OVERRIDE;
 
   // Removes |download| from the active and in progress maps.
   // Called when the download is cancelled or has an error.
@@ -345,9 +450,12 @@ class CONTENT_EXPORT DownloadManager
   // Called when a download entry is committed to the persistent store.
   void OnDownloadItemAddedToPersistentStore(int32 download_id, int64 db_handle);
 
-  // Called when Save Page As entry is commited to the persistent store.
+  // Called when Save Page As entry is committed to the persistent store.
   void OnSavePageItemAddedToPersistentStore(int32 download_id, int64 db_handle);
 
+  // For unit tests only.
+  virtual void SetFileManager(DownloadFileManager* file_manager) OVERRIDE;
+
   // |downloads_| is the owning set for all downloads known to the
   // DownloadManager.  This includes downloads started by the user in
   // this session, downloads initialized from the history system, and
@@ -420,7 +528,7 @@ class CONTENT_EXPORT DownloadManager
   // For debugging only.
   int64 largest_db_handle_in_history_;
 
-  DISALLOW_COPY_AND_ASSIGN(DownloadManager);
+  DISALLOW_COPY_AND_ASSIGN(DownloadManagerImpl);
 };
 
 #endif  // CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_MANAGER_H_