mac: Attempt to fix startup regression after r174653 more

chrome/browser/ui/cocoa/tabs/tab_strip_controller.mm

Index: chrome/browser/ui/cocoa/tabs/tab_strip_controller.mm
diff --git a/chrome/browser/ui/cocoa/tabs/tab_strip_controller.mm b/chrome/browser/ui/cocoa/tabs/tab_strip_controller.mm
index ef3997d2ecb0104d0bd6ade5d0070c88a94d2f98..dfb04d24ee697530b224a93a6f8a18e1aa4cee66 100644
--- a/chrome/browser/ui/cocoa/tabs/tab_strip_controller.mm
+++ b/chrome/browser/ui/cocoa/tabs/tab_strip_controller.mm
@@ -172,8 +172,7 @@ NSImage* CreateImageWithSize(NSSize size,
                  samplesPerPixel:4
                         hasAlpha:YES
                         isPlanar:NO
-                  colorSpaceName:NSCalibratedRGBColorSpace
-                    bitmapFormat:NSAlphaFirstBitmapFormat

[sail, 2013/01/04 22:03:35]

Does this help because it prevents a format conversion? Seems like a good idea
to leave this out anyways.

[Nico, 2013/01/04 22:05:55]

I think this is the default, I omitted this part for brevity.

+                  colorSpaceName:NSDeviceRGBColorSpace

[sail, 2013/01/04 22:03:35]

Does this help because it now matches the destination color space or because it
matches the source image color space?

If it's the second then can we grab the color space from the source images and
use it here.

If it's the first then should we document that?

[Nico, 2013/01/04 22:05:55]

I don't know if it helps. Resource images are loaded with the
kCGGenericColorspace (or how that's called); not sure if that's intentional. So
previously this wouldn't cause a conversion, but it would at paint time. Now it
converts earlier. I'm thinking that the drawing code runs more often, so this
might help. Hard to say in advance though.

If it doesn't help, I can try grabbing the source colorspace :-)

[sail, 2013/01/04 23:51:33]

ok, sounds like best practice would be to create a bitmap with the destination
color space.

                      bytesPerRow:0
                     bitsPerPixel:0];
     [bmpImageRep setSize:size];