Properly set ShelfAlignment during login

ash/shelf/shelf_layout_manager.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ash/shelf/shelf_layout_manager.h"
 
 #include <algorithm>
 #include <cmath>
 #include <cstring>
 #include <string>
@@ skipping 228 matching lines @@
       (state_.visibility_state == SHELF_VISIBLE ||
        (state_.visibility_state == SHELF_AUTO_HIDE &&
         state_.auto_hide_state == SHELF_AUTO_HIDE_SHOWN));
 }
 
 bool ShelfLayoutManager::SetAlignment(ShelfAlignment alignment) {
   if (alignment_ == alignment)
     return false;
 
   alignment_ = alignment;
-  if (Shell::GetInstance()->session_state_delegate()->IsUserSessionBlocked() ||
-      state_.is_adding_user_screen) {
-    // The shelf will itself move to the bottom while locked. If a request is
-    // sent to move while being locked, we postpone the move until the lock
-    // screen goes away.
+  // The shelf will itself move to the bottom while locked or obscured by user
+  // login. If a request is sent to move while being obscured, we postpone the
+  // move until the user session is resumed.
+  if (IsAlignmentLocked())
     return false;
-  }
 
   // This should not be called during the lock screen transitions.
   shelf_->SetAlignment(alignment);
   LayoutShelf();
   return true;
 }
 
 ShelfAlignment ShelfLayoutManager::GetAlignment() const {
   // When the screen is locked or a user gets added, the shelf is forced into
-  // bottom alignment. Note: We cannot use state_.is_screen_locked here since
-  // that flag gets set later than the SessionStateDelegate reports a locked
-  // screen which leads in
-  if (Shell::GetInstance()->session_state_delegate()->IsUserSessionBlocked() ||
-      state_.is_adding_user_screen)
+  // bottom alignment.
+  if (IsAlignmentLocked())
     return SHELF_ALIGNMENT_BOTTOM;
   return alignment_;
 }
 
 gfx::Rect ShelfLayoutManager::GetIdealBounds() {
   gfx::Rect bounds(
       ScreenUtil::GetDisplayBoundsInParent(shelf_->GetNativeView()));
   int width = 0, height = 0;
   GetShelfSize(&width, &height);
   return SelectValueForShelfAlignment(
@@ skipping 872 matching lines @@
     UpdateShelfVisibilityAfterLoginUIChange();
     return;
   }
   TargetBounds target_bounds;
   CalculateTargetBounds(state_, &target_bounds);
   UpdateBoundsAndOpacity(target_bounds, true, NULL);
   UpdateVisibilityState();
 }
 
 void ShelfLayoutManager::UpdateShelfVisibilityAfterLoginUIChange() {
-  shelf_->SetAlignment(state_.is_adding_user_screen || state_.is_screen_locked ?
-                           SHELF_ALIGNMENT_BOTTOM : alignment_);
+  shelf_->SetAlignment(GetAlignment());
   UpdateVisibilityState();
   LayoutShelf();
 }
 
+bool ShelfLayoutManager::IsAlignmentLocked() const {
+  SessionStateDelegate* session_state_delegate =

[James Cook, 2015/02/17 20:03:36]

nit: move this lower down, closer to where it is used

+      Shell::GetInstance()->session_state_delegate();
+  if (state_.is_screen_locked)
+    return true;
+  // The session state becomes active at the start of transitioning to a user
+  // session, however the session is considered blocked until the full UI is
+  // ready. Exit early to allow for proper layout.
+  if (session_state_delegate->GetSessionState() ==
+      SessionStateDelegate::SESSION_STATE_ACTIVE) {
+    return false;
+  }
+  if (session_state_delegate->IsUserSessionBlocked() ||
+      state_.is_adding_user_screen) {
+    return true;
+  }
+  return false;
+}
+
 }  // namespace ash