Fixed the bug that Drive doesn't appear on Files App on epehmeral mode.

components/drive/chromeos/file_cache.cc

Index: components/drive/chromeos/file_cache.cc
diff --git a/components/drive/chromeos/file_cache.cc b/components/drive/chromeos/file_cache.cc
index 1e6c145d8124d6ff25c04a5f50d414ace9e35c8b..892d95b176d669ff40d7523b71fff3ad4c070cb7 100644
--- a/components/drive/chromeos/file_cache.cc
+++ b/components/drive/chromeos/file_cache.cc
@@ -94,20 +94,36 @@ FileAttributes GetFileAttributes(const base::FilePath& path) {
 
 // Marks the cache file to be removable by cryptohome.
 bool SetRemovable(const base::FilePath& path) {
+  // Returns always true as a quick fix for http://crbug.com/650268.
+  // TODO(oka): Ideally we should avoid to call the method if the underlying
+  // filesystem does not support file attributes, as tmpfs for ephemeral mode.

[fukino, 2016/10/12 10:34:29]

Can we just return at the beginning of this function at the beginning of
FixMetadataAndFileAttributes() when we are on tmpfs?

[oka, 2016/10/13 05:55:51]

That's right. I updated the TODO comment.

   FileAttributes flags = GetFileAttributes(path);
-  if (flags < 0) return false;
+  if (flags < 0) {
+    // TODO(oka): false should be returned.
+    return true;
+  }
   if ((flags & FS_NODUMP_FL) == FS_NODUMP_FL) return true;
 
-  return SetFileAttributes(path, flags | FS_NODUMP_FL);
+  SetFileAttributes(path, flags | FS_NODUMP_FL);
+  // TODO(oka): Return value of the above method should be returned.
+  return true;
 }
 
 // Marks the cache file to be unremovable by cryptohome.
 bool UnsetRemovable(const base::FilePath& path) {
+  // Returns always true as a quick fix for http://crbug.com/650268.
+  // TODO(oka): Ideally we should avoid to call the method if the underlying
+  // filesystem does not support file attributes, as tmpfs for ephemeral mode.
   FileAttributes flags = GetFileAttributes(path);
-  if (flags < 0) return false;
+  if (flags < 0) {
+    // TODO(oka): false should be returned.
+    return true;
+  }
   if ((flags & FS_NODUMP_FL) == 0) return true;
 
-  return SetFileAttributes(path, flags & ~FS_NODUMP_FL);
+  SetFileAttributes(path, flags & ~FS_NODUMP_FL);
+  // TODO(oka): Return value of the above method should be returned.
+  return true;
 }
 
 // Marks |path| as drive cache dir.
@@ -649,7 +665,10 @@ bool FileCache::Initialize() {
   // Run this every time to resolve inconsistency between metadata
   // and file attributes which possibly occurs on abrupt power failure.
   if (!FixMetadataAndFileAttributes()) {
-    return false;
+    // Returning true as a quick fix for http://crbug.com/650268.
+    // TODO(oka): Ideally we should avoid to call the method if the underlying
+    // filesystem does not support file attributes, as tmpfs for ephemeral mode.
+    return true;
   }
 
   return true;