Fixes for getting themes to work well with Windows High DPI.

Fixes for getting themes to work well with Windows High DPI.

The changes are to use the GetScaleForScaleFactor function to get the scale instead
of GetImageScale. The latter function returns the current display scale on Windows which
causes themes to break. The other change is in the ctor of the BrowserThemePack class
where we add SCALE_FACTOR_100P to the list of supported scales as it is needed for default
theme packs to work correctly.

BUG=362979
R=oshima@chromium.org, pkotwicz@chromium.org, oshima

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=271999

[oshima, 2014-05-20 06:43:17]

lgtm

[ananta, 2014-05-20 17:25:30]

+pkotwicz for owners approval

[pkotwicz, 2014-05-20 19:33:01]

LGTM with important nit

https://codereview.chromium.org/296643002/diff/1/chrome/browser/themes/browse...
File chrome/browser/themes/browser_theme_pack.cc (right):

https://codereview.chromium.org/296643002/diff/1/chrome/browser/themes/browse...
chrome/browser/themes/browser_theme_pack.cc:757: << "from those supported by
platform.";
We should return NULL in this case. Otherwise we will get weird results as
|scale_factors_| changes over time

https://codereview.chromium.org/296643002/diff/1/chrome/browser/themes/browse...
chrome/browser/themes/browser_theme_pack.cc:928: // On Windows with high DPI
SCALE_FACTOR_100P may not be supported by default
Nit: missing period.

[ananta, 2014-05-20 21:49:34]

https://codereview.chromium.org/296643002/diff/1/chrome/browser/themes/browse...
File chrome/browser/themes/browser_theme_pack.cc (right):

https://codereview.chromium.org/296643002/diff/1/chrome/browser/themes/browse...
chrome/browser/themes/browser_theme_pack.cc:757: << "from those supported by
platform.";
On 2014/05/20 19:33:01, pkotwicz wrote:
> We should return NULL in this case. Otherwise we will get weird results as
> |scale_factors_| changes over time

Done.

https://codereview.chromium.org/296643002/diff/1/chrome/browser/themes/browse...
chrome/browser/themes/browser_theme_pack.cc:928: // On Windows with high DPI
SCALE_FACTOR_100P may not be supported by default
On 2014/05/20 19:33:01, pkotwicz wrote:
> Nit: missing period.

Done.

[ananta, 2014-05-20 21:54:15]

The CQ bit was checked by ananta@chromium.org

[commit-bot: I haz the power, 2014-05-20 21:55:57]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/ananta@chromium.org/296643002/20001

[commit-bot: I haz the power, 2014-05-21 20:02:25]

FYI, CQ is re-trying this CL (attempt #1).
Please consider checking whether the failures are real,
and report flakes to chrome-troopers@google.com.
The failing builders are:
  android_dbg_triggered_tests on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/android_dbg_triggered...)

[ananta, 2014-05-21 22:50:38]

Committed patchset #2 manually as r271999 (presubmit successful).