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

ash/common/shelf/wm_shelf.cc

Index: ash/common/shelf/wm_shelf.cc
diff --git a/ash/common/shelf/wm_shelf.cc b/ash/common/shelf/wm_shelf.cc
index 87392334d4f62b39757a7cd339b14da401701d69..a86a9915a3f02315610627c1a69a46971b185e69 100644
--- a/ash/common/shelf/wm_shelf.cc
+++ b/ash/common/shelf/wm_shelf.cc
@@ -166,22 +166,22 @@ int WmShelf::PrimaryAxisValue(int horizontal, int vertical) const {
 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(
@@ -309,7 +309,7 @@ ShelfView* WmShelf::GetShelfViewForTesting() {
   return shelf_view_;
 }
 
-WmShelf::WmShelf() {}
+WmShelf::WmShelf() : time_last_auto_hide_change_(base::TimeTicks::Now()) {}
 
 WmShelf::~WmShelf() {}