Move state machines to state_machines subdir

Move state machines to state_machines subdir

This CL moves state machine related files to
core/editing/state_machines.

This CL also changes BackspaceStateMachine to be able to use same template
implementation for other state machine, e.g.
GraphemeBoundaryStateMachine.

This CL also replaces the Backspace implementation with
BackspaceStateMachine.

BUG=594920
Committed: https://crrev.com/dfedcc28b89073b53d791cc51fa305c87e68567c
Cr-Commit-Position: refs/heads/master@{#384235}

[Seigo Nonaka, 2016-03-29 16:15:25]

nona@chromium.org changed reviewers:
+ yosin@chromium.org

[Seigo Nonaka, 2016-03-29 16:15:25]

Hi Yosi-san,

Could you kindly take a look?

Thank you.

[Seigo Nonaka, 2016-03-29 19:53:09]

Patchset #2 (id:20001) has been deleted

[yosin_UTC9, 2016-03-30 01:58:41]

https://codereview.chromium.org/1839753005/diff/40001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/editing/BackspaceStateMachine.cpp (right):

https://codereview.chromium.org/1839753005/diff/40001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/editing/BackspaceStateMachine.cpp:45: return
State::Unknown;
I think we should not call |BackspaceStateMachine::feedFollowingCodeUnit()|,
since |BacksapceStateMachine| never request following code units.
So, |NOTREACHED()| is better.

https://codereview.chromium.org/1839753005/diff/40001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/editing/BackspaceStateMachine.h (right):

https://codereview.chromium.org/1839753005/diff/40001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/editing/BackspaceStateMachine.h:32: // This
method must be called after feedPrecedingCodeUnit() returns PreparationDone.
|enum class State| doesn't have member |PreparationDone|.

[yosin_UTC9, 2016-03-30 04:44:27]

https://codereview.chromium.org/1839753005/diff/40001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/editing/BackspaceStateMachine.h (right):

https://codereview.chromium.org/1839753005/diff/40001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/editing/BackspaceStateMachine.h:29: State
feedPrecedingCodeUnit(UChar codeUnit);
BTW, how do we specify no preceding characters, e.g. we're at start of document?
For previous position usage, it is OK to check start of document at caller and
don't call state machine.
For next position usage, we call state machine at start of document.

[Seigo Nonaka, 2016-03-30 06:58:57]

Thank you for your review.
Please take an another look.

https://codereview.chromium.org/1839753005/diff/40001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/editing/BackspaceStateMachine.cpp (right):

https://codereview.chromium.org/1839753005/diff/40001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/editing/BackspaceStateMachine.cpp:45: return
State::Unknown;
On 2016/03/30 01:58:41, Yosi_UTC9 wrote:
> I think we should not call |BackspaceStateMachine::feedFollowingCodeUnit()|,
> since |BacksapceStateMachine| never request following code units.
> So, |NOTREACHED()| is better.

Done.

https://codereview.chromium.org/1839753005/diff/40001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/editing/BackspaceStateMachine.h (right):

https://codereview.chromium.org/1839753005/diff/40001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/editing/BackspaceStateMachine.h:29: State
feedPrecedingCodeUnit(UChar codeUnit);
On 2016/03/30 04:44:27, Yosi_UTC9 wrote:
> BTW, how do we specify no preceding characters, e.g. we're at start of
document?
> For previous position usage, it is OK to check start of document at caller and
> don't call state machine.
> For next position usage, we call state machine at start of document.

Yes this is the reason why I can't put NOTREACHED to the feedFollowingCodeUnit.
I introduced notifyEndOfPRecedingText() to be able to notify the end of
preceding text.

https://codereview.chromium.org/1839753005/diff/40001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/editing/BackspaceStateMachine.h:32: // This
method must be called after feedPrecedingCodeUnit() returns PreparationDone.
On 2016/03/30 01:58:41, Yosi_UTC9 wrote:
> |enum class State| doesn't have member |PreparationDone|.

Done.

[yosin_UTC9, 2016-03-30 07:43:07]

https://codereview.chromium.org/1839753005/diff/60001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/editing/BackspaceStateMachine.cpp (right):

https://codereview.chromium.org/1839753005/diff/60001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/editing/BackspaceStateMachine.cpp:56: return
State::Unknown;
|Invalid| is better for here? Because state machine moves into unexpected state
rather than unknown state.

https://codereview.chromium.org/1839753005/diff/60001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/editing/BackspaceStateMachine.h (right):

https://codereview.chromium.org/1839753005/diff/60001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/editing/BackspaceStateMachine.h:32: State
notifyEndOfPrecedingText();
How about |tellEndOfPrecedingText()|. It seems |notifyXXX| is used with
observers.

https://codereview.chromium.org/1839753005/diff/60001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/editing/EditingUtilities.cpp (right):

https://codereview.chromium.org/1839753005/diff/60001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/editing/EditingUtilities.cpp:550: constexpr
typename StateMachine::State NeedMoreCodeUnit =
StateMachine::State::NeedMoreCodeUnit;
Sorry, |constexpr| is still banned feature. But, it should not be banned soon,
since we migrated to MSVS2015.
http://chromium-cpp.appspot.com/#core-blacklist

https://codereview.chromium.org/1839753005/diff/60001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/editing/EditingUtilities.cpp:566: const int
length = str.length();
DCHECK_EQ(StateMachine::State::NeedFollowingCodeUnit, state);

https://codereview.chromium.org/1839753005/diff/60001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/editing/EditingUtilities.cpp:598:
DCHECK(static_cast<unsigned>(current - 1) < text.length());
Oops, DCHECK_LT(static_cast<unsigned>(current), text.length());

[Seigo Nonaka, 2016-03-30 08:13:09]

Thank you for your quick review.
I extracted machine state enum from BackspaceStateMachine.h since it can be used
by other state machine.

Could you kindly take a look again?

Thank you.

https://codereview.chromium.org/1839753005/diff/60001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/editing/BackspaceStateMachine.cpp (right):

https://codereview.chromium.org/1839753005/diff/60001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/editing/BackspaceStateMachine.cpp:56: return
State::Unknown;
On 2016/03/30 07:43:06, Yosi_UTC9 wrote:
> |Invalid| is better for here? Because state machine moves into unexpected
state
> rather than unknown state.

Done.

https://codereview.chromium.org/1839753005/diff/60001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/editing/BackspaceStateMachine.h (right):

https://codereview.chromium.org/1839753005/diff/60001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/editing/BackspaceStateMachine.h:32: State
notifyEndOfPrecedingText();
On 2016/03/30 07:43:07, Yosi_UTC9 wrote:
> How about |tellEndOfPrecedingText()|. It seems |notifyXXX| is used with
> observers.

Done.

https://codereview.chromium.org/1839753005/diff/60001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/editing/EditingUtilities.cpp (right):

https://codereview.chromium.org/1839753005/diff/60001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/editing/EditingUtilities.cpp:550: constexpr
typename StateMachine::State NeedMoreCodeUnit =
StateMachine::State::NeedMoreCodeUnit;
On 2016/03/30 07:43:07, Yosi_UTC9 wrote:
> Sorry, |constexpr| is still banned feature. But, it should not be banned soon,
> since we migrated to MSVS2015.
> http://chromium-cpp.appspot.com/#core-blacklist

Sure, to address DCHECK_EQ in following comments, I extracted this state to the
new header since same values will be used by other state machine.

https://codereview.chromium.org/1839753005/diff/60001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/editing/EditingUtilities.cpp:566: const int
length = str.length();
On 2016/03/30 07:43:07, Yosi_UTC9 wrote:
> DCHECK_EQ(StateMachine::State::NeedFollowingCodeUnit, state);

Done.

https://codereview.chromium.org/1839753005/diff/60001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/editing/EditingUtilities.cpp:598:
DCHECK(static_cast<unsigned>(current - 1) < text.length());
On 2016/03/30 07:43:07, Yosi_UTC9 wrote:
> Oops, DCHECK_LT(static_cast<unsigned>(current), text.length());

Done.

[yosin_UTC9, 2016-03-30 08:52:23]

https://codereview.chromium.org/1839753005/diff/80001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/core.gypi (right):

https://codereview.chromium.org/1839753005/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/core.gypi:1480: 'editing/StateMachineCommon.cpp',
Can we have editing/state_machines/? 
We'll have
 - StateMachineCommon.h
 - BackspaceStateMachine.{cpp,h}
 - PreviousStateMachine.{cpp,h}
 - NextStateMachine.{cpp,h}
 - and more?

https://codereview.chromium.org/1839753005/diff/80001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/editing/BackspaceStateMachine.h (right):

https://codereview.chromium.org/1839753005/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/editing/BackspaceStateMachine.h:20: enum class
State {
Should we use |MachineState| defined in "StateMachineCommon.h" instead of
|BackspaceStateMachine::State|?

https://codereview.chromium.org/1839753005/diff/80001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/editing/StateMachineCommon.h (right):

https://codereview.chromium.org/1839753005/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/editing/StateMachineCommon.h:1: // Copyright 2016
The Chromium Authors. All rights reserved.
"MachineState.h" is better since this file contains only |enum class
MachineState|.

https://codereview.chromium.org/1839753005/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/editing/StateMachineCommon.h:13: enum class
MachineState {
|MachineState| is generic term. We need to have specific one.
Fumm... |StateMachineState|? "state machine" is generic.

How about |TextSegmentationMachine|? Or, better one.

https://codereview.chromium.org/1839753005/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/editing/StateMachineCommon.h:20: CORE_EXPORT
std::ostream& operator << (std::ostream&, MachineState);
No need to have spaces around |<<|

[Seigo Nonaka, 2016-03-30 09:13:23]

Thank you for your quick review.

Please take an another look.
Thank you.

https://codereview.chromium.org/1839753005/diff/80001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/core.gypi (right):

https://codereview.chromium.org/1839753005/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/core.gypi:1480: 'editing/StateMachineCommon.cpp',
On 2016/03/30 08:52:23, Yosi_UTC9 wrote:
> Can we have editing/state_machines/? 
> We'll have
>  - StateMachineCommon.h
>  - BackspaceStateMachine.{cpp,h}
>  - PreviousStateMachine.{cpp,h}
>  - NextStateMachine.{cpp,h}
>  - and more?

Sure, done.

https://codereview.chromium.org/1839753005/diff/80001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/editing/BackspaceStateMachine.h (right):

https://codereview.chromium.org/1839753005/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/editing/BackspaceStateMachine.h:20: enum class
State {
On 2016/03/30 08:52:23, Yosi_UTC9 wrote:
> Should we use |MachineState| defined in "StateMachineCommon.h" instead of
> |BackspaceStateMachine::State|?

Ugh, yes, I'm sorry my brain was messed up by rebasing.
This should be removed.

https://codereview.chromium.org/1839753005/diff/80001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/editing/StateMachineCommon.h (right):

https://codereview.chromium.org/1839753005/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/editing/StateMachineCommon.h:1: // Copyright 2016
The Chromium Authors. All rights reserved.
On 2016/03/30 08:52:23, Yosi_UTC9 wrote:
> "MachineState.h" is better since this file contains only |enum class
> MachineState|.

Sure. To meet /MachineState/TextSegmentationMachineState/ also changed this name
to TextSegmentationMachineState.h

https://codereview.chromium.org/1839753005/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/editing/StateMachineCommon.h:13: enum class
MachineState {
On 2016/03/30 08:52:23, Yosi_UTC9 wrote:
> |MachineState| is generic term. We need to have specific one.
> Fumm... |StateMachineState|? "state machine" is generic.
> 
> How about |TextSegmentationMachine|? Or, better one.

Done.

https://codereview.chromium.org/1839753005/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/editing/StateMachineCommon.h:20: CORE_EXPORT
std::ostream& operator << (std::ostream&, MachineState);
On 2016/03/30 08:52:23, Yosi_UTC9 wrote:
> No need to have spaces around |<<|

Done.

[yosin_UTC9, 2016-03-30 09:48:13]

yosin@chromium.org changed reviewers:
+ tkent@chromium.org

[yosin_UTC9, 2016-03-30 09:48:14]

lgtm

+tkent@ for core/ chagnes

https://codereview.chromium.org/1839753005/diff/120001/third_party/WebKit/Sou...
File
third_party/WebKit/Source/core/editing/state_machines/TextSegmentationMachineState.cpp
(right):

https://codereview.chromium.org/1839753005/diff/120001/third_party/WebKit/Sou...
third_party/WebKit/Source/core/editing/state_machines/TextSegmentationMachineState.cpp:14:
switch (state) {
Just FYI: this is a personal preference.

static const char* const texts[] = {
    "Invalid", "NeedMoreCodeUnit", "NeedFollowingCodeUnit", "Finished",
};

const auto& it = std::begin(texts) + static_cast<size_t>(state);
if (it < std::begin(text) || it >= std::end(text)) {
    NOTREACHED() << state;
    return os << "???"
}
return os << *it;

https://codereview.chromium.org/1839753005/diff/120001/third_party/WebKit/Sou...
File
third_party/WebKit/Source/core/editing/state_machines/TextSegmentationMachineState.h
(right):

https://codereview.chromium.org/1839753005/diff/120001/third_party/WebKit/Sou...
third_party/WebKit/Source/core/editing/state_machines/TextSegmentationMachineState.h:14:
Invalid, // Indicates the state machine is in invalid state.
nit: Could you format comment in 80-chars?

e.g.
enum class TextSegmentationMachineState {
    // Indicates the state machine is in invalid state.
    Invalid,
    // Indicates the state machine needs more code units to transit the state.
    NeedMoreCodeUnit,
    // Indicates the state machine needs following code units to transit the
    //state.
    NeedFollowingCodeUnit,
    // Indicates the state machine found a boundary.
    Finished,
};

[Seigo Nonaka, 2016-03-30 10:03:59]

Thank you for your review!

Kent-san, please take a look!

Thank you.

https://codereview.chromium.org/1839753005/diff/120001/third_party/WebKit/Sou...
File
third_party/WebKit/Source/core/editing/state_machines/TextSegmentationMachineState.cpp
(right):

https://codereview.chromium.org/1839753005/diff/120001/third_party/WebKit/Sou...
third_party/WebKit/Source/core/editing/state_machines/TextSegmentationMachineState.cpp:14:
switch (state) {
On 2016/03/30 09:48:14, Yosi_UTC9 wrote:
> Just FYI: this is a personal preference.
> 
> static const char* const texts[] = {
>     "Invalid", "NeedMoreCodeUnit", "NeedFollowingCodeUnit", "Finished",
> };
> 
> const auto& it = std::begin(texts) + static_cast<size_t>(state);
> if (it < std::begin(text) || it >= std::end(text)) {
>     NOTREACHED() << state;
>     return os << "???"
> }
> return os << *it;

Oh, I didn't know enum class can be casted to integer safely.
I personally prefer DCHECK rather than outputting "???".
Updated.

https://codereview.chromium.org/1839753005/diff/120001/third_party/WebKit/Sou...
File
third_party/WebKit/Source/core/editing/state_machines/TextSegmentationMachineState.h
(right):

https://codereview.chromium.org/1839753005/diff/120001/third_party/WebKit/Sou...
third_party/WebKit/Source/core/editing/state_machines/TextSegmentationMachineState.h:14:
Invalid, // Indicates the state machine is in invalid state.
On 2016/03/30 09:48:14, Yosi_UTC9 wrote:
> nit: Could you format comment in 80-chars?
> 
> e.g.
> enum class TextSegmentationMachineState {
>     // Indicates the state machine is in invalid state.
>     Invalid,
>     // Indicates the state machine needs more code units to transit the state.
>     NeedMoreCodeUnit,
>     // Indicates the state machine needs following code units to transit the
>     //state.
>     NeedFollowingCodeUnit,
>     // Indicates the state machine found a boundary.
>     Finished,
> };

Done.

[Seigo Nonaka, 2016-03-30 13:13:29]

Description was changed from

==========
Change the interface of state machine.

This CL changes BackspaceStateMachine to be able to use same template
implementation for other state machine, e.g.
GraphemeBoundaryStateMachine.

This CL also replaces the Backspace implementation with
BackspaceStateMachine.

BUG=594920
==========

to

==========
Move state machines to state_machines subdir

This CL moves state machine related files to
core/editing/state_machines.

This CL also changes BackspaceStateMachine to be able to use same template
implementation for other state machine, e.g.
GraphemeBoundaryStateMachine.

This CL also replaces the Backspace implementation with
BackspaceStateMachine.

BUG=594920
==========

[tkent, 2016-03-30 23:09:46]

https://codereview.chromium.org/1839753005/diff/140001/third_party/WebKit/Sou...
File
third_party/WebKit/Source/core/editing/state_machines/BackspaceStateMachine.cpp
(right):

https://codereview.chromium.org/1839753005/diff/140001/third_party/WebKit/Sou...
third_party/WebKit/Source/core/editing/state_machines/BackspaceStateMachine.cpp:12:
const TextSegmentationMachineState Invalid =
TextSegmentationMachineState::Invalid;
This violates both of Chromium coding style and Blink coding style.
Const variables should start with 'k' (Chromium) or a lowercase letter (Blink).

https://codereview.chromium.org/1839753005/diff/140001/third_party/WebKit/Sou...
File
third_party/WebKit/Source/core/editing/state_machines/BackspaceStateMachineTest.cpp
(right):

https://codereview.chromium.org/1839753005/diff/140001/third_party/WebKit/Sou...
third_party/WebKit/Source/core/editing/state_machines/BackspaceStateMachineTest.cpp:12:
const TextSegmentationMachineState NeedMoreCodeUnit =
TextSegmentationMachineState::NeedMoreCodeUnit;
Ditto.

[Seigo Nonaka, 2016-03-31 03:50:49]

Thank you for your review. I addressed your comments.
Please take an another look.

https://codereview.chromium.org/1839753005/diff/140001/third_party/WebKit/Sou...
File
third_party/WebKit/Source/core/editing/state_machines/BackspaceStateMachine.cpp
(right):

https://codereview.chromium.org/1839753005/diff/140001/third_party/WebKit/Sou...
third_party/WebKit/Source/core/editing/state_machines/BackspaceStateMachine.cpp:12:
const TextSegmentationMachineState Invalid =
TextSegmentationMachineState::Invalid;
On 2016/03/30 23:09:46, tkent wrote:
> This violates both of Chromium coding style and Blink coding style.
> Const variables should start with 'k' (Chromium) or a lowercase letter
(Blink).

Done.

https://codereview.chromium.org/1839753005/diff/140001/third_party/WebKit/Sou...
File
third_party/WebKit/Source/core/editing/state_machines/BackspaceStateMachineTest.cpp
(right):

https://codereview.chromium.org/1839753005/diff/140001/third_party/WebKit/Sou...
third_party/WebKit/Source/core/editing/state_machines/BackspaceStateMachineTest.cpp:12:
const TextSegmentationMachineState NeedMoreCodeUnit =
TextSegmentationMachineState::NeedMoreCodeUnit;
On 2016/03/30 23:09:46, tkent wrote:
> Ditto.

Done.

[tkent, 2016-03-31 05:22:48]

lgtm

[Seigo Nonaka, 2016-03-31 05:37:08]

The CQ bit was checked by nona@chromium.org

[Seigo Nonaka, 2016-03-31 05:37:09]

The patchset sent to the CQ was uploaded after l-g-t-m from yosin@chromium.org
Link to the patchset: https://codereview.chromium.org/1839753005/#ps160001
(title: "Fix style errr")

[commit-bot: I haz the power, 2016-03-31 05:37:36]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1839753005/160001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1839753005/160001

[commit-bot: I haz the power, 2016-03-31 05:42:48]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-03-31 05:42:49]

Try jobs failed on following builders:
  linux_chromium_rel_ng on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[Seigo Nonaka, 2016-03-31 05:45:58]

The CQ bit was checked by nona@chromium.org

[commit-bot: I haz the power, 2016-03-31 05:46:17]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1839753005/160001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1839753005/160001

[commit-bot: I haz the power, 2016-03-31 06:23:47]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-03-31 06:23:48]

Try jobs failed on following builders:
  linux_chromium_chromeos_rel_ng on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[Seigo Nonaka, 2016-03-31 09:18:39]

The CQ bit was checked by nona@chromium.org

[commit-bot: I haz the power, 2016-03-31 09:19:03]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1839753005/160001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1839753005/160001

[commit-bot: I haz the power, 2016-03-31 09:53:56]

Description was changed from

==========
Move state machines to state_machines subdir

This CL moves state machine related files to
core/editing/state_machines.

This CL also changes BackspaceStateMachine to be able to use same template
implementation for other state machine, e.g.
GraphemeBoundaryStateMachine.

This CL also replaces the Backspace implementation with
BackspaceStateMachine.

BUG=594920
==========

to

==========
Move state machines to state_machines subdir

This CL moves state machine related files to
core/editing/state_machines.

This CL also changes BackspaceStateMachine to be able to use same template
implementation for other state machine, e.g.
GraphemeBoundaryStateMachine.

This CL also replaces the Backspace implementation with
BackspaceStateMachine.

BUG=594920
==========

[commit-bot: I haz the power, 2016-03-31 09:54:01]

Committed patchset #8 (id:160001)

[commit-bot: I haz the power, 2016-03-31 09:58:16]

Description was changed from

==========
Move state machines to state_machines subdir

This CL moves state machine related files to
core/editing/state_machines.

This CL also changes BackspaceStateMachine to be able to use same template
implementation for other state machine, e.g.
GraphemeBoundaryStateMachine.

This CL also replaces the Backspace implementation with
BackspaceStateMachine.

BUG=594920
==========

to

==========
Move state machines to state_machines subdir

This CL moves state machine related files to
core/editing/state_machines.

This CL also changes BackspaceStateMachine to be able to use same template
implementation for other state machine, e.g.
GraphemeBoundaryStateMachine.

This CL also replaces the Backspace implementation with
BackspaceStateMachine.

BUG=594920

Committed: https://crrev.com/dfedcc28b89073b53d791cc51fa305c87e68567c
Cr-Commit-Position: refs/heads/master@{#384235}
==========

[commit-bot: I haz the power, 2016-03-31 09:58:17]

Patchset 8 (id:??) landed as
https://crrev.com/dfedcc28b89073b53d791cc51fa305c87e68567c
Cr-Commit-Position: refs/heads/master@{#384235}