Changes threshold frequency for investigation (based on video in the bug)

ash/common/shelf/wm_shelf.cc

 // Copyright 2016 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/common/shelf/wm_shelf.h"
 
 #include "ash/common/shelf/shelf_controller.h"
 #include "ash/common/shelf/shelf_delegate.h"
 #include "ash/common/shelf/shelf_item_delegate.h"
 #include "ash/common/shelf/shelf_layout_manager.h"
@@ skipping 148 matching lines @@
   return bottom;
 }
 
 int WmShelf::PrimaryAxisValue(int horizontal, int vertical) const {
   return IsHorizontalAlignment() ? horizontal : vertical;
 }
 
 void WmShelf::SetAutoHideBehavior(ShelfAutoHideBehavior auto_hide_behavior) {
   DCHECK(shelf_layout_manager_);
 
+  if (auto_hide_behavior_ == auto_hide_behavior)
+    return;
+
   // Force a stack dump when this method is invoked too frequently.
   // This block is here temporary to help investigate http://crbug.com/665093 .
-  constexpr int kAutoHideRepeatInterval = 10000;
-  constexpr int kMaxAutoHideChangesIn10Seconds = 100;
+  constexpr int kAutoHideRepeatInterval = 1000;
+  constexpr int kMaxAutoHideChanges = 20;
   if ((base::TimeTicks::Now() - time_last_auto_hide_change_).InMilliseconds() <
       kAutoHideRepeatInterval) {
-    if (++count_auto_hide_changes_ > kMaxAutoHideChangesIn10Seconds)
+    if (++count_auto_hide_changes_ > kMaxAutoHideChanges)
       CHECK(false);
   } else {
     count_auto_hide_changes_ = 0;
   }
   time_last_auto_hide_change_ = base::TimeTicks::Now();
 
-  if (auto_hide_behavior_ == auto_hide_behavior)
-    return;
-
   auto_hide_behavior_ = auto_hide_behavior;
   WmShell::Get()->shelf_controller()->NotifyShelfAutoHideBehaviorChanged(this);
   WmShell::Get()->NotifyShelfAutoHideBehaviorChanged(
       GetWindow()->GetRootWindow());
 }
 
 ShelfAutoHideState WmShelf::GetAutoHideState() const {
   return shelf_layout_manager_->auto_hide_state();
 }
 
@@ skipping 107 matching lines @@
 }
 
 ShelfLockingManager* WmShelf::GetShelfLockingManagerForTesting() {
   return shelf_locking_manager_.get();
 }
 
 ShelfView* WmShelf::GetShelfViewForTesting() {
   return shelf_view_;
 }
 
-WmShelf::WmShelf() {}
+WmShelf::WmShelf() : time_last_auto_hide_change_(base::TimeTicks::Now()) {}
 
 WmShelf::~WmShelf() {}
 
 void WmShelf::WillDeleteShelfLayoutManager() {
   DCHECK(shelf_layout_manager_);
   shelf_layout_manager_->RemoveObserver(this);
   shelf_layout_manager_ = nullptr;
 }
 
 void WmShelf::WillChangeVisibilityState(ShelfVisibilityState new_state) {
   for (auto& observer : observers_)
     observer.WillChangeVisibilityState(new_state);
 }
 
 void WmShelf::OnAutoHideStateChanged(ShelfAutoHideState new_state) {
   for (auto& observer : observers_)
     observer.OnAutoHideStateChanged(new_state);
 }
 
 void WmShelf::OnBackgroundUpdated(ShelfBackgroundType background_type,
                                   BackgroundAnimatorChangeType change_type) {
   if (background_type == GetBackgroundType())
     return;
   for (auto& observer : observers_)
     observer.OnBackgroundTypeChanged(background_type, change_type);
 }
 
 }  // namespace ash