Allow upgrading to 2x DSF for lower UI scale when 2x resoruces are available.

Allow upgrading to 2x DSF for lower UI scale when 2x resoruces are available.

We'll test this on device to make decision, and
evisit options page after that.

BUG=361672
TEST=DisplayManager.UIScaleUpgradeToHighDPI

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=263012

[Jun Mukai, 2014-04-09 18:16:40]

lgtm with nits

https://codereview.chromium.org/230683003/diff/110001/ash/display/display_inf...
File ash/display/display_info.cc (right):

https://codereview.chromium.org/230683003/diff/110001/ash/display/display_inf...
ash/display/display_info.cc:26: bool allow_upgrade_to_high_dpi = false;
usually global variables are using g_ prefix?

https://codereview.chromium.org/230683003/diff/110001/ash/display/display_info.h
File ash/display/display_info.h (right):

https://codereview.chromium.org/230683003/diff/110001/ash/display/display_inf...
ash/display/display_info.h:85: // (<1.0f) is specificed on 1x device to make UI
sharp, e.g, upgrade 0.6
typo: specified?

https://codereview.chromium.org/230683003/diff/110001/ash/display/display_inf...
ash/display/display_info.h:139: float GetEffectiveDeviceScaleFactor() const;
a bit confused because the order of declaration of UIScale() and
DeviceScaleFactor() is different from the comment (the comment is saying
DSF->UIScale).

[oshima, 2014-04-10 14:22:22]

https://codereview.chromium.org/230683003/diff/110001/ash/display/display_inf...
File ash/display/display_info.cc (right):

https://codereview.chromium.org/230683003/diff/110001/ash/display/display_inf...
ash/display/display_info.cc:26: bool allow_upgrade_to_high_dpi = false;
On 2014/04/09 18:16:40, Jun Mukai wrote:
> usually global variables are using g_ prefix?

variables in anonymous namespace has file scope/internal linkage (strictly
speaking it's a C++11 spec tho), so this is ok.

https://codereview.chromium.org/230683003/diff/110001/ash/display/display_info.h
File ash/display/display_info.h (right):

https://codereview.chromium.org/230683003/diff/110001/ash/display/display_inf...
ash/display/display_info.h:85: // (<1.0f) is specificed on 1x device to make UI
sharp, e.g, upgrade 0.6
On 2014/04/09 18:16:40, Jun Mukai wrote:
> typo: specified?

Done.

https://codereview.chromium.org/230683003/diff/110001/ash/display/display_inf...
ash/display/display_info.h:139: float GetEffectiveDeviceScaleFactor() const;
On 2014/04/09 18:16:40, Jun Mukai wrote:
> a bit confused because the order of declaration of UIScale() and
> DeviceScaleFactor() is different from the comment (the comment is saying
> DSF->UIScale).

Fixed the comment.

[oshima, 2014-04-10 14:23:02]

The CQ bit was checked by oshima@chromium.org

[commit-bot: I haz the power, 2014-04-10 14:23:09]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/oshima@chromium.org/230683003/130001

[commit-bot: I haz the power, 2014-04-10 16:52:38]

Change committed as 263012