views::Label displaying the tooltip should not elide.

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/command_line.h"
 #include "base/location.h"
@@ skipping 80 matching lines @@
       : controller_(controller),
         widget_(NULL) {
     label_.set_background(
         views::Background::CreateSolidBackground(kTooltipBackground));
     if (CommandLine::ForCurrentProcess()->HasSwitch(switches::kNoDropShadows)) {
       label_.set_border(
           views::Border::CreateSolidBorder(kTooltipBorderWidth,
                                            kTooltipBorder));
     }
     label_.set_owned_by_client();
+    label_.SetMultiLine(true);
   }
 
   virtual ~Tooltip() {
     if (widget_) {
       widget_->RemoveObserver(this);
       widget_->Close();
     }
   }
 
   // Updates the text on the tooltip and resizes to fit.
   void SetText(aura::Window* window,
                const string16& tooltip_text,
                const gfx::Point& location) {
     int max_width, line_count;
     string16 trimmed_text(tooltip_text);
     controller_->TrimTooltipToFit(
         controller_->GetMaxWidth(location), &trimmed_text, &max_width,
         &line_count);
     label_.SetText(trimmed_text);
 
     int width = max_width + 2 * kTooltipHorizontalPadding;
-    int height = label_.GetPreferredSize().height() +
+    int height = label_.GetHeightForWidth(max_width) +
         2 * kTooltipVerticalPadding;
     if (CommandLine::ForCurrentProcess()->HasSwitch(switches::kNoDropShadows)) {
       width += 2 * kTooltipBorderWidth;
       height += 2 * kTooltipBorderWidth;
     }
     CreateWidgetIfNecessary(window);
     SetTooltipBounds(location, width, height);
   }
 
   // Shows the tooltip.
@@ skipping 377 matching lines @@
   if (!root)
     return false;
   aura::client::CursorClient* cursor_client =
       aura::client::GetCursorClient(root);
   // |cursor_client| may be NULL in tests, treat NULL as always visible.
   return !cursor_client || cursor_client->IsCursorVisible();
 }
 
 }  // namespace corewm
 }  // namespace views