Disable sync for default apps

chrome/common/extensions/extension.cc

Index: chrome/common/extensions/extension.cc
diff --git a/chrome/common/extensions/extension.cc b/chrome/common/extensions/extension.cc
index 03bba03247001607407bbad7e3a594fe3ba3d415..1b9a07925074c4f4e5228e38268fa06753756328 100644
--- a/chrome/common/extensions/extension.cc
+++ b/chrome/common/extensions/extension.cc
@@ -3776,9 +3776,11 @@ Extension::SyncType Extension::GetSyncType() const {
 bool Extension::IsSyncable() const {
   // TODO(akalin): Figure out if we need to allow some other types.
 
-  // We want to sync any extensions that are internal and the chrome web store.
-  return location() == Extension::INTERNAL ||
-      id() == extension_misc::kWebStoreAppId;
+  // Sync  internal externsions except default apps.

[Mihai Parparita -not on Chrome, 2012/08/24 21:05:23]

Extra space before internal, and there's a typo in "externsions".

Also, this comment just says what the code does, which makes it redundant. It's
better to explain why we don't sync default apps, Something like: "Default apps
are not synced because otherwise they will pollute profiles that don't already
have them. Specifically, if a user doesn't have default apps, creates a new
profile (which gets default apps) and then enables sync for it, then their
profile everywhere gets the default apps."

+  bool is_syncable = (location() ==  Extension::INTERNAL && !from_default());
+  // sync the chrome web store.

[Mihai Parparita -not on Chrome, 2012/08/24 21:05:23]

Another redundant comment. Based on http://crrev.com/132065, it looks like we
sync the Web Store because we want its position on the new tab page to be
synced. Maybe say that instead?

+  is_syncable |= (id() ==  extension_misc::kWebStoreAppId);
+  return is_syncable;
 }
 
 bool Extension::ShouldDisplayInLauncher() const {