Evict drive cache with file download from website if necessary.

chrome/browser/chromeos/drive/download_handler.h

Index: chrome/browser/chromeos/drive/download_handler.h
diff --git a/chrome/browser/chromeos/drive/download_handler.h b/chrome/browser/chromeos/drive/download_handler.h
index 9973224c1b5c5fad0aa60af49d60f97ce55ee510..983d384ee3e3bd383871a5ece503f003dd328d87 100644
--- a/chrome/browser/chromeos/drive/download_handler.h
+++ b/chrome/browser/chromeos/drive/download_handler.h
@@ -73,6 +73,14 @@ class DownloadHandler : public AllDownloadItemNotifier::Observer {
       const content::DownloadItem* download,
       const content::CheckForFileExistenceCallback& callback);
 
+  // Checks available storage space and free disk space if necessary for
+  // |download|. If |immediate| is false, execution is delayed and rate limited.
+  void FreeDiskSpaceIfNeeded(const content::DownloadItem* download,
+                             bool immediate);

[hashimoto, 2015/10/28 09:06:16]

Generally, boolean parameters make the code less readable.
(cf. "nullptr/NULL, true/false, 1, 2, 3..." section of our style guide
https://google-styleguide.googlecode.com/svn/trunk/cppguide.html#Implementati...)

How about passing base::TimeDelta instead?

[yawano, 2015/10/29 02:52:43]

Split a method into two methods, FreeDiskSpaceIfNeeded and
FreeDiskSpaceIfNeededImmediately.

+
+  // Sets free disk space delay for testing.
+  void SetFreeDiskSpaceDelayForTesting(const base::TimeDelta& delay);
+
  private:
   // AllDownloadItemNotifier::Observer overrides:
   void OnDownloadCreated(content::DownloadManager* manager,
@@ -98,12 +106,15 @@ class DownloadHandler : public AllDownloadItemNotifier::Observer {
                         const base::FilePath* cache_file_path,
                         FileError error);
 
+  void ExecuteFreeDiskSpaceIfNeededFor();
+
   // Gets a download manager, given a |manager_id| casted from the pointer to
   // the manager. This is used to validate the manager that may be deleted while
   // asynchronous task posting. Returns NULL if the manager is already gone.
   content::DownloadManager* GetDownloadManager(void* manager_id);
 
   FileSystemInterface* file_system_;  // Owned by DriveIntegrationService.
+
   // Observe the DownloadManager for new downloads.
   scoped_ptr<AllDownloadItemNotifier> notifier_;
   scoped_ptr<AllDownloadItemNotifier> notifier_incognito_;
@@ -111,6 +122,11 @@ class DownloadHandler : public AllDownloadItemNotifier::Observer {
   // Temporary download location directory.
   base::FilePath drive_tmp_download_path_;
 
+  // Pending requested space. 0 is set if there is no request.
+  int64 pending_request_space_;
+
+  base::TimeDelta free_disk_space_delay_;
+
   // Note: This should remain the last member so it'll be destroyed and
   // invalidate its weak pointers before any other members are destroyed.
   base::WeakPtrFactory<DownloadHandler> weak_ptr_factory_;