Use shorter max length for tooltip text on Windows

ui/views/corewm/tooltip_controller.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 "ui/views/corewm/tooltip_controller.h"
 
 #include <vector>
 
 #include "base/strings/string_util.h"
 #include "base/time/time.h"
@@ skipping 10 matching lines @@
 #include "ui/views/corewm/tooltip.h"
 #include "ui/views/widget/tooltip_manager.h"
 #include "ui/wm/public/drag_drop_client.h"
 
 namespace views {
 namespace corewm {
 namespace {
 
 const int kTooltipTimeoutMs = 500;
 const int kDefaultTooltipShownTimeoutMs = 10000;
+#if defined(OS_WIN)
+// Drawing a long word in tooltip is very slow on Windows. crbug.com/513693
+const size_t kMaxTooltipLength = 1024;
+#else
 const size_t kMaxTooltipLength = 2048;
+#endif
 
 // Returns true if |target| is a valid window to get the tooltip from.
 // |event_target| is the original target from the event and |target| the window
 // at the same location.
 bool IsValidTarget(aura::Window* event_target, aura::Window* target) {
   if (!target || (event_target == target))
     return true;
 
   void* event_target_grouping_id = event_target->GetNativeWindowProperty(
       TooltipManager::kGroupingPropertyKey);
@@ skipping 324 matching lines @@
     return;
   if (tooltip_window_)
     tooltip_window_->RemoveObserver(this);
   tooltip_window_ = target;
   if (tooltip_window_)
     tooltip_window_->AddObserver(this);
 }
 
 }  // namespace corewm
 }  // namespace views