Fix scrollbar transparency / opacity issues on Windows.

Get rid of recursive calls into NativeThemeWin::Paint, rather,
separate it into Paint, PaintDirect, and PaintIndirect (formerly
PaintToNonPlatformCanvas).

Force "known problematic UI elements" to go through the 
PaintIndirect path to fix-up their alpha values.  This list
includes scrollbars in Windows XP or Windows Vista+ with
the Windows Classic theme enabled.

BUG=131588, 133881, 24524
TEST=

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=148215

[brettw, 2012-07-23 21:27:07]

LGTM, just style nits.

https://chromiumcodereview.appspot.com/10807023/diff/1/ui/base/native_theme/n...
File ui/base/native_theme/native_theme_win.cc (right):

https://chromiumcodereview.appspot.com/10807023/diff/1/ui/base/native_theme/n...
ui/base/native_theme/native_theme_win.cc:290: bool needsPaintIndirect = false;
Style: "needs_paint_indirect"

https://chromiumcodereview.appspot.com/10807023/diff/1/ui/base/native_theme/n...
ui/base/native_theme/native_theme_win.cc:306: if (!GetThemeHandle(SCROLLBAR)) {
No {} for single-line conditionals (to match surrounding style).

[ccameron, 2012-07-23 23:20:36]

Thanks!  Fixed.

https://chromiumcodereview.appspot.com/10807023/diff/1/ui/base/native_theme/n...
File ui/base/native_theme/native_theme_win.cc (right):

https://chromiumcodereview.appspot.com/10807023/diff/1/ui/base/native_theme/n...
ui/base/native_theme/native_theme_win.cc:290: bool needsPaintIndirect = false;
On 2012/07/23 21:27:07, brettw wrote:
> Style: "needs_paint_indirect"

Done.

https://chromiumcodereview.appspot.com/10807023/diff/1/ui/base/native_theme/n...
ui/base/native_theme/native_theme_win.cc:306: if (!GetThemeHandle(SCROLLBAR)) {
On 2012/07/23 21:27:07, brettw wrote:
> No {} for single-line conditionals (to match surrounding style).
Done (and made this change to the "if (needs_paint_indirect)" block)

[commit-bot: I haz the power, 2012-07-23 23:52:22]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/ccameron@chromium.org/10807023/4001

[commit-bot: I haz the power, 2012-07-23 23:52:25]

Presubmit check for 10807023-4001 failed and returned exit status 1.

Running presubmit commit checks ...

** Presubmit Messages **
If this change requires manual test instructions to QA team, add
TEST=[instructions].

** Presubmit ERRORS **
Missing LGTM from an OWNER for files in these directories:
    ui

[ccameron, 2012-07-24 01:02:27]

Adding sky and ben to review (OWNERS for the ui directory) -- can one of you
take a look at this?

[ccameron, 2012-07-24 01:03:53]

Adding sky and ben to review (OWNERS for the ui directory) -- can one of you
take a look at this?

(for real this time)

[sky, 2012-07-24 04:34:22]

LGTM

[Alexei Svitkine (slow), 2012-07-24 13:58:19]

LGTM

[commit-bot: I haz the power, 2012-07-24 20:25:36]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/ccameron@chromium.org/10807023/4001

[commit-bot: I haz the power, 2012-07-24 21:59:04]

Change committed as 148215