chromeos: Make CheckIdleStateIsLocked() query D-Bus client.

Make the Chrome OS implementation of
CheckIdleStateIsLocked() (used by the chrome.idle API) get
the lock state from chromeos::SessionManagerClient instead
of depending on ash::SessionStateDelegate (which reaches
into chrome/browser/chromeos/login/). This makes it possible
for the idle code to be later moved under ui/base/ instead
of living in chrome/browser/, permitting the chrome.idle API
to be moved from chrome/ to extensions/.

As part of this, make SessionManagerClient cache the
most-recently-received-from-session_manager screen-lock
state. Previously it just passed state updates to its
observers, but the idle functions lack a class that can
register itself as an observer.

BUG=446320

Review URL: https://codereview.chromium.org/852453005

Cr-Commit-Position: refs/heads/master@{#311333}

1 files changed, 1 insertions, 0 deletions

diff --git a/chromeos/dbus/mock_session_manager_client.h b/chromeos/dbus/mock_session_manager_client.h
index cdc5d6d..3a88e52 100644
--- a/chromeos/dbus/mock_session_manager_client.h
+++ b/chromeos/dbus/mock_session_manager_client.h
@@ -22,6 +22,7 @@ class MockSessionManagerClient : public SessionManagerClient {
   MOCK_METHOD1(AddObserver, void(Observer*));
   MOCK_METHOD1(RemoveObserver, void(Observer*));
   MOCK_CONST_METHOD1(HasObserver, bool(const Observer*));
+  MOCK_CONST_METHOD0(IsScreenLocked, bool(void));
   MOCK_METHOD0(EmitLoginPromptVisible, void(void));
   MOCK_METHOD2(RestartJob, void(int, const std::string&));
   MOCK_METHOD1(StartSession, void(const std::string&));