[Smart Lock, Prefs reconciliation] Prefs migration logic for desktop platforms.

components/password_manager/core/common/password_manager_pref_names.h

Index: components/password_manager/core/common/password_manager_pref_names.h
diff --git a/components/password_manager/core/common/password_manager_pref_names.h b/components/password_manager/core/common/password_manager_pref_names.h
index dc138f9d130cbd1be62e4d4b336b8252fd81739a..4ff3cd7af94df33c32b6fa0e170d551438ec59c7 100644
--- a/components/password_manager/core/common/password_manager_pref_names.h
+++ b/components/password_manager/core/common/password_manager_pref_names.h
@@ -21,6 +21,10 @@ extern const char kAllowToCollectURLBubbleWasShown[];
 // period, in which the "Allow to collect URL?" bubble can be shown.
 extern const char kAllowToCollectURLBubbleActivePeriodStartFactor[];
 
+// The value of this preference controls whenever Password Manager will save and

[vabr (Chromium), 2015/08/07 08:48:02]

Please explain (in the comment) the relation to kPasswordManagerSavingEnabled.

[melandory, 2015/08/12 09:03:24]

Done.

+// fill credentials.

[vabr (Chromium), 2015/08/07 08:48:02]

Is the part about filling actually true? Currently, there is no way to disable
filling other than deleting the credentials, and this CL does not seem to
introduce this functionality.

[engedy, 2015/08/07 11:41:38]

Well, technically, the setting will not control anything as of this CL, that
will come later.

I think we should add a TODO that we still need to wire in this preference and
change the behavior so that it controls both saving and filling.

[vabr (Chromium), 2015/08/07 11:56:19]

+1

+extern const char kCredentialEnableService[];

[engedy, 2015/08/07 11:41:38]

I'd actually dare propose that we make use of the extra level of indirection
here introduced by having a constant, and give the constant an actually
meaningful name, such as |kPasswordManagerEnabledNew|. Then, once it is wired
in, we could rename it to |kPasswordManagerEnabled| and change the existing
setting to |kPasswordManagerSavingEnabledLegacy|.

WDYT?

[vabr (Chromium), 2015/08/07 11:56:19]

This sounds good, but also the current state (with the typo fixed) works for me.
One drawback of the suggested name switching (in addition to the once more CL to
do the switch) is that |kPasswordManagerEnabled| will mean two different things
in code of different age, which might be confusing when investigating problems
on a branch etc.
So my weak preference is actually to let the constant name match its content.

[melandory, 2015/08/12 09:03:24]

It's also seems to me that it's better to let the constant name match its
content.

+
 #if !defined(OS_MACOSX) && !defined(OS_CHROMEOS) && defined(OS_POSIX)
 // The local profile id for this profile.
 extern const char kLocalProfileId[];