Defer preparing for overview until all overview items are initialized.

BUG=384495

Review URL: https://codereview.chromium.org/363133002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@281918 0039d316-1c4b-4281-b951-d872f2087c98

ash/wm/overview/window_grid.cc

@@ -137,7 +137,6 @@ WindowGrid::WindowGrid(aura::Window* root_window,
       continue;
     (*iter)->AddObserver(this);
     observed_windows_.insert(*iter);
-    WindowSelectorItem* item = NULL;
 
     if ((*iter)->type() == ui::wm::WINDOW_TYPE_PANEL &&
         wm::GetWindowState(*iter)->panel_attached()) {
@@ -148,20 +147,12 @@ WindowGrid::WindowGrid(aura::Window* root_window,
         window_list_.push_back(panels_item);
       }
       panels_item->AddWindow(*iter);
-      item = panels_item;
     } else {
-      item = new WindowSelectorWindow(*iter);
-      item->PrepareForOverview();
-      window_list_.push_back(item);
+      window_list_.push_back(new WindowSelectorWindow(*iter));
     }
   }
   if (window_list_.empty())
     return;
-
-  if (panels_item)
-    panels_item->PrepareForOverview();
-
-  PositionWindows(true);
 }
 
 WindowGrid::~WindowGrid() {
@@ -171,6 +162,13 @@ WindowGrid::~WindowGrid() {
   }
 }
 
+void WindowGrid::PrepareForOverview() {
+  for (ScopedVector<WindowSelectorItem>::iterator iter = window_list_.begin();
+       iter != window_list_.end(); ++iter) {
+    (*iter)->PrepareForOverview();
+  }
+}
+
 void WindowGrid::PositionWindows(bool animate) {
   CHECK(!window_list_.empty());
 

ash/wm/overview/window_grid.h

@@ -51,6 +51,10 @@ class ASH_EXPORT WindowGrid : public aura::WindowObserver {
              WindowSelector* window_selector);
   virtual ~WindowGrid();
 
+  // Prepares the windows in this grid for overview. This will restore all
+  // minimized windows and ensure they are visible.
+  void PrepareForOverview();
+
   // Positions all the windows in the grid.
   void PositionWindows(bool animate);
 

ash/wm/overview/window_selector.cc

@@ -179,6 +179,15 @@ WindowSelector::WindowSelector(const WindowList& windows,
     grid_list_.push_back(grid.release());
   }
 
+  // Do not call PrepareForOverview until all items are added to window_list_ as
+  // we don't want to cause any window updates until all windows in overview
+  // are observed. See http://crbug.com/384495.
+  for (ScopedVector<WindowGrid>::iterator iter = grid_list_.begin();
+       iter != grid_list_.end(); ++iter) {
+    (*iter)->PrepareForOverview();
+    (*iter)->PositionWindows(true);
+  }
+
   DCHECK(!grid_list_.empty());
   UMA_HISTOGRAM_COUNTS_100("Ash.WindowSelector.Items", num_items_);