Omnibox UI: Confine Cocoa suggestion lines to a single-line.

chrome/browser/ui/cocoa/omnibox/omnibox_popup_cell.mm

 // Copyright 2013 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.
 
 #import "chrome/browser/ui/cocoa/omnibox/omnibox_popup_cell.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 #include <cmath>
@@ skipping 618 matching lines @@
 
 - (CGFloat)drawMatchPart:(NSAttributedString*)attributedString
                withFrame:(NSRect)cellFrame
                   origin:(NSPoint)origin
             withMaxWidth:(int)maxWidth
             forDarkTheme:(BOOL)isDarkTheme {
   NSRect renderRect = NSIntersectionRect(
       cellFrame, NSOffsetRect(cellFrame, origin.x, origin.y));
   renderRect.size.width =
       std::min(NSWidth(renderRect), static_cast<CGFloat>(maxWidth));
+  renderRect.size.height = std::min(NSWidth(renderRect), kDefaultTextHeight);
   if (!NSIsEmptyRect(renderRect)) {
     [attributedString drawWithRect:FlipIfRTL(renderRect, cellFrame)
                            options:NSStringDrawingUsesLineFragmentOrigin |
                                    NSStringDrawingTruncatesLastVisibleLine];
   }
   return NSWidth(renderRect);
 }
 
 + (CGFloat)computeContentsOffset:(const AutocompleteMatch&)match {
   const base::string16& inputText = base::UTF8ToUTF16(
@@ skipping 74 matching lines @@
 }
 
 + (CGFloat)getContentTextHeightForDoubleLine:(BOOL)isDoubleLine {
   CGFloat height = kDefaultTextHeight + 2 * GetVerticalMargin();
   if (isDoubleLine)
     height += kDefaultTextHeight + kDefaultVerticalMargin;
   return height;
 }
 
 @end