Fix issue 29996

Fix issue 29996

WM_SETICON with NULL does not restore the icon on taskbar and caused
issue 29996. The fix is to figure out an icon to use after throbber
animation finishes and use that icon with WM_SETICON.

BUG=29996
TEST=Verify fix for issue 29996.

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=40548

[xiyuan, 2010-03-02 23:02:47]

Issue 29996 happens because taskbar does not restore window icon to class icon.
It's hard to believe but it is true for all Windows (including XP, Vista and
Win7). The ideal solution would be find out a way to notify taskbar about the
icon change like WM_SETICON with a valid icon handle. However, I failed to find
such a solution. :(

Things I have tried:
1. Hide/Show the window: Works but window flickers;
2. Modify window styles: Does not work;
3. ITaskbarList->DeletaTab/AddTab. Works for XP/Vista but not work for Win7 and
user would see the taskbar button disappear and show up again;

This CL uses a valid icon handle with WM_SETICON to circumvent the taskbar
problem. The icon to use after throbber animation is either a valid window icon
(set by WM_SETICON) or the class icon.

Cheers
Xiyuan

[brettw, 2010-03-03 17:57:13]

Can you do GetClassInfoEx to get the class' WNDCLASSEX and use the HICON out of
that in a SetIcon call?

[xiyuan, 2010-03-03 18:11:31]

On 2010/03/03 17:57:13, brettw wrote:
> Can you do GetClassInfoEx to get the class' WNDCLASSEX and use the HICON out
of
> that in a SetIcon call?

Yeah, this is similar to what I did in the CL. I use GetClassLongPtr to get the
class icon if the frame window does not have an overridden icon before throbber
starts.

[brettw, 2010-03-03 18:35:52]

I mean, can we do the GetClassLong at the time we want to reset the icon to
avoid saving the "HICON to restore" before we start the animation. I wouldn't
expect WM_SETICON to change the class' icon, only the Window's one.

[xiyuan, 2010-03-03 19:06:24]

On 2010/03/03 18:35:52, brettw wrote:
> I mean, can we do the GetClassLong at the time we want to reset the icon to
> avoid saving the "HICON to restore" before we start the animation. I wouldn't
> expect WM_SETICON to change the class' icon, only the Window's one.

I did this because the window icon could be overridden from the class icon when
chrome is launched as an app.

Think you are right that we could remove the newly added frame_icon_ and infer
the icon-to-use in StopThrobber. Let me update the CL.

[xiyuan, 2010-03-03 19:39:10]

CL updated to get the reset icon in StopThrobber per discussion. Please take
another look. Thanks.

[brettw, 2010-03-03 20:13:47]

LGTM, this solution looks better.