Fix 117074: Panels [WIN]: Crash data shows a stack trace consistently involving PanelManager

chrome/browser/notifications/balloon_collection_impl.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 "chrome/browser/notifications/balloon_collection_impl.h"
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/stl_util.h"
 #include "chrome/browser/notifications/balloon.h"
@@ skipping 168 matching lines @@
     int type,
     const content::NotificationSource& source,
     const content::NotificationDetails& details) {
   gfx::Rect bounds;
   switch (type) {
     case chrome::NOTIFICATION_PANEL_CHANGED_BOUNDS:
       bounds = content::Source<Panel>(source).ptr()->GetBounds();
       // Fall through.
     case chrome::NOTIFICATION_PANEL_ADDED:
     case chrome::NOTIFICATION_PANEL_CLOSED:
+      layout_.enable_computing_panel_offset();
       if (layout_.ComputeOffsetToMoveAbovePanels(bounds))
         PositionBalloons(true);
       break;
     default:
       NOTREACHED();
       break;
   }
 }
 
 void BalloonCollectionImpl::PositionBalloonsInternal(bool reposition) {
@@ skipping 69 matching lines @@
     }
   } else {
     // Mouse moved back into the region.  Cancel the reposition.
     reposition_factory_.InvalidateWeakPtrs();
   }
 }
 #endif
 
 BalloonCollectionImpl::Layout::Layout()
     : placement_(INVALID),
+      need_to_compute_panel_offset_(false),
       offset_to_move_above_panels_(0) {
   RefreshSystemMetrics();
 }
 
 void BalloonCollectionImpl::Layout::GetMaxLinearSize(int* max_balloon_size,
                                                      int* total_size) const {
   DCHECK(max_balloon_size && total_size);
 
   // All placement schemes are vertical, so we only care about height.
   *total_size = work_area_.height();
@@ skipping 111 matching lines @@
   // restrict to the min & max sizes
   return gfx::Size(
       std::max(min_balloon_width(),
                std::min(max_balloon_width(), size.width())),
       std::max(min_balloon_height(),
                std::min(max_balloon_height(), size.height())));
 }
 
 bool BalloonCollectionImpl::Layout::ComputeOffsetToMoveAbovePanels(
     const gfx::Rect& panel_bounds) {
+  // If the offset is not enabled due to that we have not received a
+  // notification about panel, don't proceed because we don't want to call
+  // PanelManager::GetInstance() to create an instance when panel is not
+  // present.
+  if (!need_to_compute_panel_offset_)
+    return false;
+
   const DockedPanelStrip::Panels& panels =
       PanelManager::GetInstance()->docked_strip()->panels();
   int offset_to_move_above_panels = 0;
 
   // The offset is the maximum height of panels that could overlap with the
   // balloons.
   if (NeedToMoveAboveLeftSidePanels()) {
     // If the affecting panel does not lie in the balloon area, no need to
     // update the offset.
     if (!panel_bounds.IsEmpty() &&
@@ skipping 58 matching lines @@
   gfx::Rect new_work_area = gfx::Screen::GetPrimaryMonitorWorkArea();
 #endif
   if (!work_area_.Equals(new_work_area)) {
     work_area_.SetRect(new_work_area.x(), new_work_area.y(),
                        new_work_area.width(), new_work_area.height());
     changed = true;
   }
 
   return changed;
 }