Use bold for default constrained window button

chrome/browser/ui/cocoa/constrained_window/constrained_window_button.mm

 // 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.
 
 #import "chrome/browser/ui/cocoa/constrained_window/constrained_window_button.h"
 
 #include "base/memory/scoped_nsobject.h"
+#import "chrome/browser/ui/cocoa/key_equivalent_constants.h"
 #include "skia/ext/skia_utils_mac.h"
 #import "third_party/molokocacao/NSBezierPath+MCAdditions.h"
 #include "ui/gfx/scoped_ns_graphics_context_save_gstate_mac.h"
 
 namespace {
 
 enum ButtonState {
   BUTTON_NORMAL,
   BUTTON_HOVER,
   BUTTON_PRESSED,
@@ skipping 54 matching lines @@
   return shadow;
 }
 
 NSColor* GetButtonBorderColor(ButtonState button_state) {
   const SkColor color[] = {0x40000000, 0x4D000000, 0x4D000000, 0x1F000000};
 
   return gfx::SkColorToCalibratedNSColor(color[button_state]);
 }
 
 NSAttributedString* GetButtonAttributedString(NSString* title,
+                                              NSString* key_equivalent,
                                               ButtonState button_state) {
   const SkColor text_color[] = {0xFF333333, 0XFF000000, 0xFF000000, 0xFFAAAAAA};
   // The shadow color should be 0xFFF0F0F0 but that doesn't show up so use
   // pure white instead.
   const SkColor shadow_color[] =
       {0xFFFFFFFF, 0xFFFFFFFF, 0x00000000, 0xFFFFFFFF};
 
   scoped_nsobject<NSShadow> shadow([[NSShadow alloc] init]);
   [shadow setShadowColor:
       gfx::SkColorToCalibratedNSColor(shadow_color[button_state])];
   [shadow setShadowOffset:NSMakeSize(0, -1)];
   [shadow setShadowBlurRadius:0];
 
   scoped_nsobject<NSMutableParagraphStyle> paragraphStyle(
       [[NSMutableParagraphStyle alloc] init]);
   [paragraphStyle setAlignment:NSCenterTextAlignment];
 
+  NSFont* font = nil;
+  if ([key_equivalent isEqualToString:kKeyEquivalentReturn])
+    font = [NSFont boldSystemFontOfSize:12];
+  else
+    font = [NSFont systemFontOfSize:12];
+
   NSDictionary* attributes = [NSDictionary dictionaryWithObjectsAndKeys:
-      [NSFont systemFontOfSize:12], NSFontAttributeName,
+      font, NSFontAttributeName,
       gfx::SkColorToCalibratedNSColor(text_color[button_state]),
       NSForegroundColorAttributeName,
       shadow.get(), NSShadowAttributeName,
       paragraphStyle.get(), NSParagraphStyleAttributeName,
       nil];
   return [[[NSAttributedString alloc] initWithString:title
                                           attributes:attributes] autorelease];
 }
 
 }  // namespace
@@ skipping 94 matching lines @@
   // Border
   path = [NSBezierPath bezierPathWithRoundedRect:NSInsetRect(frame, 0.5, 0.5)
                                          xRadius:2
                                          yRadius:2];
   if ([[[controlView window] firstResponder] isEqual:controlView])
     [[NSColor colorWithCalibratedRed:0.30 green:0.57 blue:1.0 alpha:1.0] set];
   else
     [GetButtonBorderColor(buttonState) set];
   [path stroke];
 
-  [self drawTitle:GetButtonAttributedString([self title], buttonState)
-        withFrame:frame
-           inView:controlView];
+  NSAttributedString* title = GetButtonAttributedString(
+      [self title], [self keyEquivalent], buttonState);
+  [self drawTitle:title withFrame:frame inView:controlView];
 }
 
 - (NSSize)cellSize {
-  NSAttributedString* attributedString =
-      GetButtonAttributedString([self title], BUTTON_NORMAL);
-  NSSize size = [attributedString size];
+  NSAttributedString* title = GetButtonAttributedString(
+      [self title], [self keyEquivalent], [self buttonState]);
+  NSSize size = [title size];
   size.height = std::max(size.height, kButtonHeight);
   size.width += kButtonPaddingX * 2;
   return size;
 }
 
 - (ButtonState)buttonState {
   if (![self isEnabled])
     return BUTTON_DISABLED;
   if ([self isHighlighted])
     return BUTTON_PRESSED;
   if (isMouseInside_)
     return BUTTON_HOVER;
   return BUTTON_NORMAL;
 }
 
 @end