mac: New asset for the tabstrip border, tweak drawing.

chrome/browser/ui/cocoa/tabs/tab_strip_controller.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/tabs/tab_strip_controller.h"
 
 #import <QuartzCore/QuartzCore.h>
 
 #include <cmath>
 #include <limits>
@@ skipping 204 matching lines @@
       }
 
       [mask drawAtPoint:NSZeroPoint
                fromRect:NSMakeRect(0, 0, width, height)
               operation:NSCompositeDestinationIn
                fraction:1.0];
   }) autorelease];
 }
 
 // Paints |overlay| on top of |ground|.
-NSImage* Overlay(NSImage* ground, NSImage* overlay) {
+NSImage* Overlay(NSImage* ground, NSImage* overlay, CGFloat alpha) {
   DCHECK_EQ([ground size].width, [overlay size].width);
   DCHECK_EQ([ground size].height, [overlay size].height);
 
   return [CreateImageWithSize([ground size], ^(NSSize size) {
       CGFloat width = size.width;
       CGFloat height = size.height;
       [ground drawAtPoint:NSZeroPoint
                  fromRect:NSMakeRect(0, 0, width, height)
                 operation:NSCompositeCopy
                  fraction:1.0];
       [overlay drawAtPoint:NSZeroPoint
                   fromRect:NSMakeRect(0, 0, width, height)
                  operation:NSCompositeSourceOver
-                  fraction:1.0];
+                  fraction:alpha];
   }) autorelease];
 }
 
 }  // namespace
 
 @interface TabStripController (Private)
 - (void)addSubviewToPermanentList:(NSView*)aView;
 - (void)regenerateSubviewList;
 - (NSInteger)indexForContentsView:(NSView*)view;
 - (NSImageView*)iconImageViewForContents:(content::WebContents*)contents;
@@ skipping 1947 matching lines @@
 
   ResourceBundle& rb = ResourceBundle::GetSharedInstance();
   NSImage* mask = rb.GetNativeImageNamed(IDR_NEWTAB_BUTTON_MASK).ToNSImage();
   NSImage* normal = rb.GetNativeImageNamed(IDR_NEWTAB_BUTTON).ToNSImage();
   NSImage* hover = rb.GetNativeImageNamed(IDR_NEWTAB_BUTTON_H).ToNSImage();
   NSImage* pressed = rb.GetNativeImageNamed(IDR_NEWTAB_BUTTON_P).ToNSImage();
 
   NSImage* foreground = ApplyMask(
       theme->GetNSImageNamed(IDR_THEME_TAB_BACKGROUND, true), mask);
 
-  [[newTabButton_ cell] setImage:Overlay(foreground, normal)
+  [[newTabButton_ cell] setImage:Overlay(foreground, normal, 1.0)
                   forButtonState:image_button_cell::kDefaultState];
-  [[newTabButton_ cell] setImage:Overlay(foreground, hover)
+  [[newTabButton_ cell] setImage:Overlay(foreground, hover, 1.0)
                   forButtonState:image_button_cell::kHoverState];
-  [[newTabButton_ cell] setImage:Overlay(foreground, pressed)
+  [[newTabButton_ cell] setImage:Overlay(foreground, pressed, 1.0)
                     forButtonState:image_button_cell::kPressedState];
 
   // IDR_THEME_TAB_BACKGROUND_INACTIVE is only used with the default theme.
   if (theme->UsingDefaultTheme()) {
+    const CGFloat alpha = tabs::kImageNoFocusAlpha;
     NSImage* background = ApplyMask(
         theme->GetNSImageNamed(IDR_THEME_TAB_BACKGROUND_INACTIVE, true), mask);
-    [[newTabButton_ cell] setImage:Overlay(background, normal)
+    [[newTabButton_ cell] setImage:Overlay(background, normal, alpha)
                     forButtonState:image_button_cell::kDefaultStateBackground];
-    [[newTabButton_ cell] setImage:Overlay(background, hover)
+    [[newTabButton_ cell] setImage:Overlay(background, hover, alpha)
                     forButtonState:image_button_cell::kHoverStateBackground];
   } else {
     [[newTabButton_ cell] setImage:nil
                     forButtonState:image_button_cell::kDefaultStateBackground];
     [[newTabButton_ cell] setImage:nil
                     forButtonState:image_button_cell::kHoverStateBackground];
   }
 }
 
 @end
 
 NSView* GetSheetParentViewForWebContents(WebContents* web_contents) {
   // View hierarchy of the contents view:
   // NSView  -- switchView, same for all tabs
   // +- NSView  -- TabContentsController's view
   //    +- TabContentsViewCocoa
   //
   // Changing it? Do not forget to modify
   // -[TabStripController swapInTabAtIndex:] too.
   return [web_contents->GetNativeView() superview];
 }