Merge 241955 "Make extensions icons easier to target with gestures"

Merge 241955 "Make extensions icons easier to target with gestures"

> Make extensions icons easier to target with gestures
> 
> The bounds of a BrowserActionView and the bounds
> of its child view |button_| have the following
> properties:
> 
> - Both share a common center point.
> - The bounds of |button_| are square, but the 
> bounds of BAV are not.
> - The bounds of |button_| are contained within
> the bounds of BAV.
> - Both are small enough to be easily covered
> by a finger.
> 
> This is a flaw in rect-based targeting
> making it difficult to correctly target
> |button_| with a tap gesture. To obtain the
> desired behavior, use the distance
> between the center of the touch and the center
> of the view (instead of the center line of
> the view) to break ties among rect-based
> targeting candidates.
> 
> The use of the distance to center line was
> to avoid biases against wide or tall views. 
> But this is not necessary because any view 
> which can have at least 60% of its area 
> covered by a touch cannot be sufficiently wide 
> or tall enough to benefit from such a metric.
> 
> BUG=328182
> 
> Review URL: https://codereview.chromium.org/94003003

TBR=tdanderson@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=242156

[tdanderson, 2013-12-20 20:02:27]

Committed patchset #1 manually as r242156.