Fix disabled browser action appearance on Mac.

chrome/browser/ui/cocoa/extensions/browser_action_button.mm

Index: chrome/browser/ui/cocoa/extensions/browser_action_button.mm
diff --git a/chrome/browser/ui/cocoa/extensions/browser_action_button.mm b/chrome/browser/ui/cocoa/extensions/browser_action_button.mm
index 93fa87978383e3616d80a6c7d7c75118e876a9a2..92e1c4faeffbf6f632f970bb610d2962d4478f75 100644
--- a/chrome/browser/ui/cocoa/extensions/browser_action_button.mm
+++ b/chrome/browser/ui/cocoa/extensions/browser_action_button.mm
@@ -24,6 +24,7 @@
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/gfx/canvas_skia_paint.h"
 #include "ui/gfx/image/image.h"
+#include "ui/gfx/image/image_skia_operations.h"
 #include "ui/gfx/rect.h"
 #include "ui/gfx/scoped_ns_graphics_context_save_gstate_mac.h"
 #include "ui/gfx/size.h"
@@ -135,6 +136,8 @@ class ExtensionActionIconFactoryBridge
       forButtonState:image_button_cell::kHoverState];
     [cell setImageID:IDR_BROWSER_ACTION_P
       forButtonState:image_button_cell::kPressedState];
+    [cell setImageID:IDR_BROWSER_ACTION
+      forButtonState:image_button_cell::kDisabledState];
 
     [self setTitle:@""];
     [self setButtonType:NSMomentaryChangeButton];
@@ -247,16 +250,19 @@ class ExtensionActionIconFactoryBridge
     [self setToolTip:base::SysUTF8ToNSString(tooltip)];
   }
 
-  gfx::Image image = iconFactoryBridge_->GetIcon(tabId_);
-
-  if (!image.IsEmpty())
-    [self setImage:image.ToNSImage()];
-
-  [[self cell] setTabId:tabId_];
+  gfx::ImageSkia image = iconFactoryBridge_->GetIcon(tabId_).AsImageSkia();
 
   bool enabled = extension_->browser_action()->GetIsVisible(tabId_);
+  if (!image.isNull()) {
+    if (!enabled)
+      image = gfx::ImageSkiaOperations::CreateTransparentImage(image, 0.4);
+    [self setImage:gfx::Image(image).ToNSImage()];

[Nico, 2012/09/21 02:02:02]

It looks like we're round-tripping to skia and back just for dimming. Can you do
this in paint (see below)?

If you decide to keep it here,can you avoid the roundtrip in the "enabled" case
at least?

[Yoyo Zhou, 2012/09/21 18:04:59]

Ah, I didn't realize this was something to avoid. Doing it below seems to work.

+  }
+
   [self setEnabled:enabled ? YES : NO];

[Nico, 2012/09/21 02:02:02]

just "enabled" is enough. Drop the ?YES:NO.

[Yoyo Zhou, 2012/09/21 18:04:59]

Done.

 
+  [[self cell] setTabId:tabId_];
+
   [self setNeedsDisplay:YES];
 }