touch: Make sure the correct radius values are used for touch events.

touch: Make sure the correct radius values are used for touch events.

The device may not always report the radii values for a touch event. In such
cases, instead of making up a default value, always use 0 so that it is easy to
determine if the radius is the real radius reported by the device or not. Also,
at the same time, make sure that the radius value sent to webkit follows the
spec. Also fix the radii adjustment for device-scale-factor.

BUG=128553
TEST=manually with test-pages

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=138006

[sky, 2012-05-18 19:57:37]

http://codereview.chromium.org/10383249/diff/1/ui/aura/event.cc
File ui/aura/event.cc (right):

http://codereview.chromium.org/10383249/diff/1/ui/aura/event.cc#newcode288
ui/aura/event.cc:288: radius_x_ /= scale.x();
Are we sure these are non-zero?

[sadrul, 2012-05-18 20:07:32]

http://codereview.chromium.org/10383249/diff/1/ui/aura/event.cc
File ui/aura/event.cc (right):

http://codereview.chromium.org/10383249/diff/1/ui/aura/event.cc#newcode288
ui/aura/event.cc:288: radius_x_ /= scale.x();
On 2012/05/18 19:57:37, sky wrote:
> Are we sure these are non-zero?

Ah, good point. I think in normal cases, the scale is 1. But I have added a
check for non-zero scale before using it.

[sky, 2012-05-18 21:53:46]

LGTM