gdata: Support opening zip file on Google Docs.

Pass the file extension in the 2nd argument to DiskMountManager::MountPath
to indicate the archive format (e.g.: .zip, .rar, etc.)

When mounting and unmounting archive files in GData cache, call
GDataFileSystem::SetMountedState to set or clear the "mounted" state
accordingly.

BUG=chromium-os:28678
TEST=Verify that mounting/unmounting archive files on GData works correctly.

Review URL: http://codereview.chromium.org/10083067

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@133987 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/chrome/browser/chromeos/disks/disk_mount_manager.h b/chrome/browser/chromeos/disks/disk_mount_manager.h
index af8406f8..53aca0e 100644
--- a/chrome/browser/chromeos/disks/disk_mount_manager.h
+++ b/chrome/browser/chromeos/disks/disk_mount_manager.h
@@ -201,7 +201,9 @@
   virtual void RequestMountInfoRefresh() = 0;
 
   // Mounts a device.
-  virtual void MountPath(const std::string& source_path, MountType type) = 0;
+  virtual void MountPath(const std::string& source_path,
+                         const std::string& source_format,
+                         MountType type) = 0;
 
   // Unmounts a mounted disk.
   virtual void UnmountPath(const std::string& mount_path) = 0;