aura: Really long tooltips should be wrapped not truncated.

ash/tooltips/tooltip_controller.h

 // 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.
 
 #ifndef ASH_TOOLTIPS_TOOLTIP_CONTROLLER_H_
 #define ASH_TOOLTIPS_TOOLTIP_CONTROLLER_H_
 #pragma once
 
 #include "base/memory/scoped_ptr.h"
 #include "base/string16.h"
@@ skipping 42 matching lines @@
       aura::GestureEvent* event) OVERRIDE;
 
   // Overridden from aura::WindowObserver.
   virtual void OnWindowDestroyed(aura::Window* window) OVERRIDE;
 
  private:
   friend class ash::test::TooltipControllerTest;
 
   class Tooltip;
 
+  // Trims the tooltip to fit, setting |text| to the clipped result,
+  // |max_width| to the width (in pixels) of the clipped text and |line_count|
+  // to the number of lines of text in the tooltip. |x| and |y| give the
+  // location of the tooltip in screen coordinates.
+  static void TrimTooltipToFit(string16* text,
+                               int* max_width,
+                               int* line_count,
+                               int x,
+                               int y);
+
   void TooltipTimerFired();
 
   // Updates the tooltip if required (if there is any change in the tooltip
   // text or the aura::Window.
   void UpdateIfRequired();
 
   // Only used in tests.
   bool IsTooltipVisible();
 
   bool IsDragDropInProgress();
@@ skipping 14 matching lines @@
 
   bool tooltips_enabled_;
 
   DISALLOW_COPY_AND_ASSIGN(TooltipController);
 };
 
 }  // namespace internal
 }  // namespace ash
 
 #endif  // ASH_TOOLTIPS_TOOLTIP_CONTROLLER_H_