Bug: 3038861
Change-Id: I94011ca80710ff6eb24e940104f7d9d3bb86840a

This change refactors a key index and pointer position variables into
a separate static inner class KeyState . This change also disables
time debouncing.

Bug: 3033737
Change-Id: Ie4fc37316c260330d8f0861e0771ea903a99cfce

The space key preview should be displayed one of the following case.
- Popup preview is enabled
- Language switcher is in action, whether popup preview is enabled or
  not.

For phone number keyboard, popup preview is never displayed even if
popup preview is enabled.

Bug: 3006612
Bug: 3021091
Change-Id: I5385c776d0e8e3981fc8d8851db9140d92599ce5

Bug: 2987077
Change-Id: I971c44be121d8780ec27aa1649fd0925e249fbbc

This change also introduces MiniKeyboardKeyDetector and
mini_keyboad_slide_allowance parameter to tune the key detection
behavior.

Bug: 2993769
Change-Id: I1932b0a382e172cb77b9e098ae182049c834dfe0

On a device that has distinct multi-touch panel, pressing '123?' key
will change keyboard layout to symbol mode.  While pressing '123?'
key, you can press other symbol key to input.  Then releasing '123?'
key will change keyboard layout back to alphabet mode.

Bug: 2973383
Change-Id: I3b069fb19141820def8060db4766a08c7c0a6ff0

Bug: 2978975

Change-Id: Ie634e8ae827fe093c5c673b75d85835050b03794

Actually it was caused by canceling repeat key (space and delete) when
multiple pointer are touching.

Bug: 2975041
Change-Id: If82183b9225efdace7b5418860b9664f1705b7ec

Bug: 2973373
Change-Id: I9871c09ec8c1c2aa945d97392e61ee1ec585baef

This change also fixes bug#2973683.

Bug: 2973546
Bug: 2973683
Change-Id: I67573e5b7cad4af261591a4a608d0596dd7901f2

This change also refactors some mini-keyboard related methods in
LatinKeyboardBaseView and PointerTracker class.

Bug: 2973236
Change-Id: I3190fe89ea3ac3c6d351ed4b6d77de98a0aa65db

TODO:
- Remove close button on mini-keyboard
- Dismiss mini-keyboard when finger leave the screen while no key is selected

This change also renames some instance variables to have more meaningful name.

Bug: 2959169
Change-Id: I9fd79116a647d7be82415c6e9e7cdaf6edcb2bf6

This is follow up change of Ie6cf67681180467bd8ba35d0205ce6727b7684a2

Bug: 2959169
Change-Id: I9e4cb0c9178856ddd6049f0b751b54f3ad26a266

Bug: 2959169
Change-Id: Id2b0b974fffdf6f09ee1828e957b973d2ce1c315

This change also adds debugging log to PointerTracker class

Bug: 2959169
Change-Id: Ie6cf67681180467bd8ba35d0205ce6727b7684a2

Bug: 2910379
Change-Id: I5cfae33e72a406585137842a2260310813cee07f

Bug: 2910379
Change-Id: If2b28764dc777bb62949a95bc61c4a16ff152220

It is easier to track each pointer if a PointerTracker object keeps
its pointer id.

Bug: 2910379
Change-Id: If3e3b0cf3d834d22302598f4d85d54c9a4ce92ba

The KeyDetector abstracts key detection algorithm. The
ProximityKeyDetector is one of its concrete implementations.  Another
one that might be called XAxisKeyDetector will follow to realize the
pop-up mini-keyboard behavior described in bug#2959169.

Bug: 2959169
Change-Id: Idd3fc53282e6b721ec7a4ce500af8aba21ce07a3

Bug: 2910379
Change-Id: I179ae4359afb57c351d5fcc5f5453c30d3ef0c01

Bug: 2910379
Change-Id: Iefafa2d30ad16f898a00664e4bf3e3e88dcd2cb2

Bug: 2910379
Change-Id: I9503b2211b272a4a2903d0732985e5ab8ee39440