Mark removable Drive caches for cryptohome.

components/drive/chromeos/file_cache.h

Index: components/drive/chromeos/file_cache.h
diff --git a/components/drive/chromeos/file_cache.h b/components/drive/chromeos/file_cache.h
index 23b104c9630a9b609e4957501ac8f8fe8823e414..222fa1a939b740e08d92f3ad4b03c7047901f4f6 100644
--- a/components/drive/chromeos/file_cache.h
+++ b/components/drive/chromeos/file_cache.h
@@ -144,6 +144,10 @@ class FileCache {
   // Initializes the cache. Returns true on success.
   bool Initialize();
 
+  // Returns if Drive cache migration for crbug/533750 should be invoked.

[hashimoto, 2016/05/02 08:29:20]

nit: crbug/533750 ".com" missing.
The same goes for others

[oka, 2016/05/09 14:27:40]

Done.

+  // Public for testing.
+  bool ShouldStartDriveCacheMigration();
+
   // Destroys this cache. This function posts a task to the blocking task
   // runner to safely delete the object.
   // Must be called on the UI thread.
@@ -158,14 +162,6 @@ class FileCache {
       const ResourceMetadataStorage::RecoveredCacheInfoMap&
           recovered_cache_info);
 
-  // Migrates cache files from |from| directory to |to_files| directory with
-  // creating links in |to_links| directory if necessary. Returns true for
-  // success.
-  static bool MigrateCacheFiles(const base::FilePath& from,
-                                const base::FilePath& to_files,
-                                const base::FilePath& to_links,
-                                ResourceMetadataStorage* metadata_storage);
-
  private:
   friend class FileCacheTest;
 
@@ -191,6 +187,15 @@ class FileCache {
   // TODO(hashimoto): Remove this method at some point.
   bool RenameCacheFilesToNewFormat();
 
+  // Add appropriate file attributes to the Drive cache directory and files in

[hashimoto, 2016/05/02 08:29:20]

nit: "Add" -> "Adds".
https://google.github.io/styleguide/cppguide.html#Function_Comments
The same goes for others.

[oka, 2016/05/09 14:27:40]

Done.

Merged MigrateCacheFiles and ResolveMetadataInconsistency.

+  // it for crbug/533750. Returns true on success.
+  // Inconsistency between cache and metadata should be resolved before this

[hashimoto, 2016/05/02 08:29:20]

nit: How about "cache" -> "cache files" to avoid confusion, as everything is
related to cache in this class?

[oka, 2016/05/09 14:27:40]

Done.

+  // method is called.
+  bool MigrateCacheFiles();
+
+  // Resolve metadata inconsistency in case cryptohome removed cache files.
+  bool ResolveMetadataInconsistency();
+
   // This method must be called after writing to a cache file.
   // Used to implement OpenForWrite().
   void CloseForWrite(const std::string& id);