Fixed incorrect resize of docked windows when locking screen.

ash/shelf/shelf_layout_manager.cc

Index: ash/shelf/shelf_layout_manager.cc
diff --git a/ash/shelf/shelf_layout_manager.cc b/ash/shelf/shelf_layout_manager.cc
index 1639fc80e812edf80949959d4ab208069256afb2..b39140812c060e9f3801684e8278e5fe7a278b93 100644
--- a/ash/shelf/shelf_layout_manager.cc
+++ b/ash/shelf/shelf_layout_manager.cc
@@ -556,6 +556,7 @@ void ShelfLayoutManager::SetChildBounds(aura::Window* child,
 void ShelfLayoutManager::OnLockStateChanged(bool locked) {
   // Force the shelf to layout for alignment (bottom if locked, restore
   // the previous alignment otherwise).
+  state_.is_screen_locked = locked;
   shelf_->SetAlignment(locked ? SHELF_ALIGNMENT_BOTTOM : alignment_);
   UpdateVisibilityState();
   LayoutShelf();
@@ -590,8 +591,6 @@ void ShelfLayoutManager::SetState(ShelfVisibilityState visibility_state) {
   State state;
   state.visibility_state = visibility_state;
   state.auto_hide_state = CalculateAutoHideState(visibility_state);
-  state.is_screen_locked =
-      Shell::GetInstance()->session_state_delegate()->IsScreenLocked();
   state.window_state = workspace_controller_ ?
       workspace_controller_->GetWindowState() : WORKSPACE_WINDOW_STATE_DEFAULT;
 
@@ -721,8 +720,10 @@ void ShelfLayoutManager::UpdateBoundsAndOpacity(
       ScreenUtil::ConvertRectToScreen(
           shelf_->status_area_widget()->GetNativeView()->parent(),
           status_bounds));
-  Shell::GetInstance()->SetDisplayWorkAreaInsets(
-      root_window_, target_bounds.work_area_insets);
+  if (!state_.is_screen_locked) {
+    Shell::GetInstance()->SetDisplayWorkAreaInsets(
+        root_window_, target_bounds.work_area_insets);
+  }
 }
 
 void ShelfLayoutManager::StopAnimating() {
@@ -1147,6 +1148,9 @@ void ShelfLayoutManager::OnDockBoundsChanging(
 
 void ShelfLayoutManager::OnLockStateEvent(LockStateObserver::EventType event) {
   if (event == EVENT_LOCK_ANIMATION_STARTED) {
+    // Enter the screen locked state as the animation starts to prevent
+    // layout changes as the screen locks.
+    state_.is_screen_locked = true;
     // Hide the status area widget (using auto hide animation).
     base::AutoReset<ShelfVisibilityState> state(&state_.visibility_state,
                                                 SHELF_HIDDEN);