[Android] Expose native ViewConfiguration constants as DIPs

[Android] Expose native ViewConfiguration constants as DIPs

Touch-related constants in Android's ViewConfiguration are exposed in
device pixels. However, all native code that uses these values need
DIPs. Rather than relying on the caller to do the scaling, which may be
incorrect for external displays with different densities, expose the
constants as DIPs directly.

Longer term, we should instead use a context-specific lookup for
ViewConfiguration values.

BUG=310763
Committed: https://crrev.com/dcebeec14cf284e8d936e906bde40a80c1ae65ad
Cr-Commit-Position: refs/heads/master@{#338114}

[jdduke (slow), 2015-07-09 17:04:52]

jdduke@chromium.org changed reviewers:
+ gsennton@chromium.org

[jdduke (slow), 2015-07-09 17:04:53]

gsennton@: PTAL. As discussed offline, I think we're OK using the DisplayMetrics
density for the conversion here.

[gsennton, 2015-07-09 17:27:08]

lgtm (which i guess has no power here)

https://codereview.chromium.org/1216933013/diff/1/ui/android/java/src/org/chr...
File ui/android/java/src/org/chromium/ui/gfx/ViewConfigurationHelper.java
(right):

https://codereview.chromium.org/1216933013/diff/1/ui/android/java/src/org/chr...
ui/android/java/src/org/chromium/ui/gfx/ViewConfigurationHelper.java:57: // The
ViewConfiguration will differ only if the density has changed.
Since we are density-independent now this should not need to trigger an update?
(if this comment holds...)

maybe it is an unnecessary risk to remove it though?

[jdduke (slow), 2015-07-09 17:49:00]

jdduke@chromium.org changed reviewers:
+ tedchoc@chromium.org

[jdduke (slow), 2015-07-09 17:49:01]

+tedchoc for owner review.

https://codereview.chromium.org/1216933013/diff/1/ui/android/java/src/org/chr...
File ui/android/java/src/org/chromium/ui/gfx/ViewConfigurationHelper.java
(right):

https://codereview.chromium.org/1216933013/diff/1/ui/android/java/src/org/chr...
ui/android/java/src/org/chromium/ui/gfx/ViewConfigurationHelper.java:57: // The
ViewConfiguration will differ only if the density has changed.
On 2015/07/09 17:27:08, gsennton wrote:
> Since we are density-independent now this should not need to trigger an
update?
> (if this comment holds...)
> 
> maybe it is an unnecessary risk to remove it though?

Yeah, I wondered about that. While that comment is technically true, I think it
might be dangerous to rely on it, so I'll tweak it and add an assert. I suppose
we could gate the update on whether |mDensity| changes, but that's probably
premature.

[Ted C, 2015-07-09 18:07:27]

lgtm

[jdduke (slow), 2015-07-09 18:13:34]

The CQ bit was checked by jdduke@chromium.org

[jdduke (slow), 2015-07-09 18:13:35]

The patchset sent to the CQ was uploaded after l-g-t-m from
gsennton@chromium.org
Link to the patchset: https://codereview.chromium.org/1216933013/#ps20001
(title: "Fix comment and add assert")

[commit-bot: I haz the power, 2015-07-09 18:14:21]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1216933013/20001

[commit-bot: I haz the power, 2015-07-09 19:33:14]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-07-09 19:34:17]

Patchset 2 (id:??) landed as
https://crrev.com/dcebeec14cf284e8d936e906bde40a80c1ae65ad
Cr-Commit-Position: refs/heads/master@{#338114}