DevTools: Diff subsystem

DevTools: Diff subsystem

This moves the diff computation out of SourceCodeDiff into a new module.
Now the diff can be shared by more than one consumer.

BUG=610061
Review-Url: https://codereview.chromium.org/2729783002
Cr-Commit-Position: refs/heads/master@{#456991}
Committed: https://chromium.googlesource.com/chromium/src/+/569f345a2ee19b54dc008c3c2011cee9e7405d36

[einbinder, 2017-03-02 02:25:37]

einbinder@chromium.org changed reviewers:
+ lushnikov@chromium.org

[einbinder, 2017-03-02 02:25:38]

ptal

[einbinder, 2017-03-04 02:11:24]

Clients request diff now instead of receiving them on DiffChangedEvent.

[lushnikov, 2017-03-04 04:00:29]

https://codereview.chromium.org/2729783002/diff/40001/third_party/WebKit/Sour...
File
third_party/WebKit/Source/devtools/front_end/source_frame/UISourceCodeFrame.js
(left):

https://codereview.chromium.org/2729783002/diff/40001/third_party/WebKit/Sour...
third_party/WebKit/Source/devtools/front_end/source_frame/UISourceCodeFrame.js:193:
this._diff.updateDiffMarkersWhenPossible();
why did these go?

https://codereview.chromium.org/2729783002/diff/40001/third_party/WebKit/Sour...
File
third_party/WebKit/Source/devtools/front_end/workspace_diff/UISourceCodeDiff.js
(right):

https://codereview.chromium.org/2729783002/diff/40001/third_party/WebKit/Sour...
third_party/WebKit/Source/devtools/front_end/workspace_diff/UISourceCodeDiff.js:11:
this.uiSourceCode = uiSourceCode;
private?

https://codereview.chromium.org/2729783002/diff/40001/third_party/WebKit/Sour...
third_party/WebKit/Source/devtools/front_end/workspace_diff/UISourceCodeDiff.js:13:
Workspace.UISourceCode.Events.WorkingCopyChanged,
this._uiSourceCodeChanged.bind(this));
don't bind, pass "this" as a third parameter

https://codereview.chromium.org/2729783002/diff/40001/third_party/WebKit/Sour...
third_party/WebKit/Source/devtools/front_end/workspace_diff/UISourceCodeDiff.js:15:
Workspace.UISourceCode.Events.WorkingCopyCommitted,
this._uiSourceCodeChanged.bind(this));
ditt

https://codereview.chromium.org/2729783002/diff/40001/third_party/WebKit/Sour...
third_party/WebKit/Source/devtools/front_end/workspace_diff/UISourceCodeDiff.js:25:
if (!uiSourceCode[WorkspaceDiff.UISourceCodeDiff.Symbol])
symbol should be private

https://codereview.chromium.org/2729783002/diff/40001/third_party/WebKit/Sour...
third_party/WebKit/Source/devtools/front_end/workspace_diff/UISourceCodeDiff.js:35:
this._requestDiffPromise = null;
can we fire event here, and defer all the actual work until the diff is
requested?

https://codereview.chromium.org/2729783002/diff/40001/third_party/WebKit/Sour...
third_party/WebKit/Source/devtools/front_end/workspace_diff/UISourceCodeDiff.js:43:
this._pendingChanges = setTimeout(emitDiffChanged.bind(this), 200);
you should throttle on the view side, not at the model side.

https://codereview.chromium.org/2729783002/diff/40001/third_party/WebKit/Sour...
third_party/WebKit/Source/devtools/front_end/workspace_diff/UISourceCodeDiff.js:57:
requestDiff() {
can we make this accept uiSourceCode as an argument and return a throw-away
object as result? the design would feel more light-weight.

Benefits:
- you would be able to name this like WorkspaceDiff
- you would have a place to put the changedSourceCodes() and other methods

Downsides:
- you'll have to implement "[un]subscribeForDiffChange(uiSourceCode)" method

[einbinder, 2017-03-07 06:03:31]

https://codereview.chromium.org/2729783002/diff/40001/third_party/WebKit/Sour...
File
third_party/WebKit/Source/devtools/front_end/source_frame/UISourceCodeFrame.js
(left):

https://codereview.chromium.org/2729783002/diff/40001/third_party/WebKit/Sour...
third_party/WebKit/Source/devtools/front_end/source_frame/UISourceCodeFrame.js:193:
this._diff.updateDiffMarkersWhenPossible();
On 2017/03/04 at 04:00:28, lushnikov wrote:
> why did these go?

There is a DiffChanged event

https://codereview.chromium.org/2729783002/diff/40001/third_party/WebKit/Sour...
File
third_party/WebKit/Source/devtools/front_end/workspace_diff/UISourceCodeDiff.js
(right):

https://codereview.chromium.org/2729783002/diff/40001/third_party/WebKit/Sour...
third_party/WebKit/Source/devtools/front_end/workspace_diff/UISourceCodeDiff.js:11:
this.uiSourceCode = uiSourceCode;
On 2017/03/04 at 04:00:28, lushnikov wrote:
> private?

Ok

https://codereview.chromium.org/2729783002/diff/40001/third_party/WebKit/Sour...
third_party/WebKit/Source/devtools/front_end/workspace_diff/UISourceCodeDiff.js:13:
Workspace.UISourceCode.Events.WorkingCopyChanged,
this._uiSourceCodeChanged.bind(this));
On 2017/03/04 at 04:00:28, lushnikov wrote:
> don't bind, pass "this" as a third parameter

Ok

https://codereview.chromium.org/2729783002/diff/40001/third_party/WebKit/Sour...
third_party/WebKit/Source/devtools/front_end/workspace_diff/UISourceCodeDiff.js:15:
Workspace.UISourceCode.Events.WorkingCopyCommitted,
this._uiSourceCodeChanged.bind(this));
On 2017/03/04 at 04:00:28, lushnikov wrote:
> ditt

Done.

https://codereview.chromium.org/2729783002/diff/40001/third_party/WebKit/Sour...
third_party/WebKit/Source/devtools/front_end/workspace_diff/UISourceCodeDiff.js:25:
if (!uiSourceCode[WorkspaceDiff.UISourceCodeDiff.Symbol])
On 2017/03/04 at 04:00:28, lushnikov wrote:
> symbol should be private

Done.

https://codereview.chromium.org/2729783002/diff/40001/third_party/WebKit/Sour...
third_party/WebKit/Source/devtools/front_end/workspace_diff/UISourceCodeDiff.js:35:
this._requestDiffPromise = null;
On 2017/03/04 at 04:00:28, lushnikov wrote:
> can we fire event here, and defer all the actual work until the diff is
requested?

Done.

https://codereview.chromium.org/2729783002/diff/40001/third_party/WebKit/Sour...
third_party/WebKit/Source/devtools/front_end/workspace_diff/UISourceCodeDiff.js:43:
this._pendingChanges = setTimeout(emitDiffChanged.bind(this), 200);
On 2017/03/04 at 04:00:28, lushnikov wrote:
> you should throttle on the view side, not at the model side.

If it doesn't get throttled here, then there is no guarantee that different
views will request the same diffs.

https://codereview.chromium.org/2729783002/diff/40001/third_party/WebKit/Sour...
third_party/WebKit/Source/devtools/front_end/workspace_diff/UISourceCodeDiff.js:57:
requestDiff() {
On 2017/03/04 at 04:00:28, lushnikov wrote:
> can we make this accept uiSourceCode as an argument and return a throw-away
object as result? the design would feel more light-weight.
> 
> Benefits:
> - you would be able to name this like WorkspaceDiff
> - you would have a place to put the changedSourceCodes() and other methods
> 
> Downsides:
> - you'll have to implement "[un]subscribeForDiffChange(uiSourceCode)" method

Made these top level functions.

[lushnikov, 2017-03-08 17:55:16]

https://codereview.chromium.org/2729783002/diff/100001/third_party/WebKit/Sou...
File
third_party/WebKit/Source/devtools/front_end/workspace_diff/UISourceCodeDiff.js
(right):

https://codereview.chromium.org/2729783002/diff/100001/third_party/WebKit/Sou...
third_party/WebKit/Source/devtools/front_end/workspace_diff/UISourceCodeDiff.js:18:
WorkspaceDiff.addThrottledDiffListener = function(uiSourceCode, callback,
thisObj) {
.subscribeToDiffChange(..)

https://codereview.chromium.org/2729783002/diff/100001/third_party/WebKit/Sou...
third_party/WebKit/Source/devtools/front_end/workspace_diff/UISourceCodeDiff.js:41:
WorkspaceDiff._UISourceCodeDiff = class extends Common.Object {
Let's do the following: 
1. introduce class WorkspaceDiff
2. make it a singleton which is created in Main.js, see workspace for example
3. embed all the static methods inside the class, defining it's api

https://codereview.chromium.org/2729783002/diff/100001/third_party/WebKit/Sou...
third_party/WebKit/Source/devtools/front_end/workspace_diff/UISourceCodeDiff.js:60:
if (!this.hasEventListeners(WorkspaceDiff.DiffChangedEvent))
we can omit this check - there's already one in the Common.Object.emit code

https://codereview.chromium.org/2729783002/diff/100001/third_party/WebKit/Sou...
third_party/WebKit/Source/devtools/front_end/workspace_diff/UISourceCodeDiff.js:64:
if (content && content.length < 65536)
typeof content === 'string'

https://codereview.chromium.org/2729783002/diff/100001/third_party/WebKit/Sou...
third_party/WebKit/Source/devtools/front_end/workspace_diff/UISourceCodeDiff.js:65:
emitDiffChanged.call(this);
let's always call the throttled event through timeout to be always asynchronous

[einbinder, 2017-03-08 23:12:47]

https://codereview.chromium.org/2729783002/diff/100001/third_party/WebKit/Sou...
File
third_party/WebKit/Source/devtools/front_end/workspace_diff/UISourceCodeDiff.js
(right):

https://codereview.chromium.org/2729783002/diff/100001/third_party/WebKit/Sou...
third_party/WebKit/Source/devtools/front_end/workspace_diff/UISourceCodeDiff.js:18:
WorkspaceDiff.addThrottledDiffListener = function(uiSourceCode, callback,
thisObj) {
On 2017/03/08 at 17:55:16, lushnikov wrote:
> .subscribeToDiffChange(..)

Done.

https://codereview.chromium.org/2729783002/diff/100001/third_party/WebKit/Sou...
third_party/WebKit/Source/devtools/front_end/workspace_diff/UISourceCodeDiff.js:41:
WorkspaceDiff._UISourceCodeDiff = class extends Common.Object {
On 2017/03/08 at 17:55:16, lushnikov wrote:
> Let's do the following: 
> 1. introduce class WorkspaceDiff
> 2. make it a singleton which is created in Main.js, see workspace for example
> 3. embed all the static methods inside the class, defining it's api

This will pull the Diff module into autostart.

https://codereview.chromium.org/2729783002/diff/100001/third_party/WebKit/Sou...
third_party/WebKit/Source/devtools/front_end/workspace_diff/UISourceCodeDiff.js:60:
if (!this.hasEventListeners(WorkspaceDiff.DiffChangedEvent))
On 2017/03/08 at 17:55:16, lushnikov wrote:
> we can omit this check - there's already one in the Common.Object.emit code

Removed.

https://codereview.chromium.org/2729783002/diff/100001/third_party/WebKit/Sou...
third_party/WebKit/Source/devtools/front_end/workspace_diff/UISourceCodeDiff.js:65:
emitDiffChanged.call(this);
On 2017/03/08 at 17:55:16, lushnikov wrote:
> let's always call the throttled event through timeout to be always
asynchronous

Done.

[lushnikov, 2017-03-09 00:09:25]

https://codereview.chromium.org/2729783002/diff/120001/third_party/WebKit/Sou...
File
third_party/WebKit/Source/devtools/front_end/workspace_diff/UISourceCodeDiff.js
(right):

https://codereview.chromium.org/2729783002/diff/120001/third_party/WebKit/Sou...
third_party/WebKit/Source/devtools/front_end/workspace_diff/UISourceCodeDiff.js:9:
WorkspaceDiff.requestDiff = function(uiSourceCode) {
Let's do WorkspaceDiff.workspaceDiff().requestDiff(..) and put all the API in
there

and rename the filename

https://codereview.chromium.org/2729783002/diff/120001/third_party/WebKit/Sou...
third_party/WebKit/Source/devtools/front_end/workspace_diff/UISourceCodeDiff.js:62:
var delay = (!content || content.length < 65536) ? 0 : 200;
extract 200 into constant

[einbinder, 2017-03-09 21:07:20]

https://codereview.chromium.org/2729783002/diff/120001/third_party/WebKit/Sou...
File
third_party/WebKit/Source/devtools/front_end/workspace_diff/UISourceCodeDiff.js
(right):

https://codereview.chromium.org/2729783002/diff/120001/third_party/WebKit/Sou...
third_party/WebKit/Source/devtools/front_end/workspace_diff/UISourceCodeDiff.js:9:
WorkspaceDiff.requestDiff = function(uiSourceCode) {
On 2017/03/09 at 00:09:25, lushnikov wrote:
> Let's do WorkspaceDiff.workspaceDiff().requestDiff(..) and put all the API in
there
> 
> and rename the filename

Done.

https://codereview.chromium.org/2729783002/diff/120001/third_party/WebKit/Sou...
third_party/WebKit/Source/devtools/front_end/workspace_diff/UISourceCodeDiff.js:62:
var delay = (!content || content.length < 65536) ? 0 : 200;
On 2017/03/09 at 00:09:25, lushnikov wrote:
> extract 200 into constant

Done.

[lushnikov, 2017-03-10 01:17:04]

https://codereview.chromium.org/2729783002/diff/180001/third_party/WebKit/Lay...
File third_party/WebKit/LayoutTests/inspector/sources/source-code-diff.html
(right):

https://codereview.chromium.org/2729783002/diff/180001/third_party/WebKit/Lay...
third_party/WebKit/LayoutTests/inspector/sources/source-code-diff.html:27:
InspectorTest.showUISourceCode(uiSourceCode, () => undefined);
 showUISourceCodePromise

https://codereview.chromium.org/2729783002/diff/180001/third_party/WebKit/Sou...
File third_party/WebKit/Source/devtools/front_end/diff/Diff.js (right):

https://codereview.chromium.org/2729783002/diff/180001/third_party/WebKit/Sou...
third_party/WebKit/Source/devtools/front_end/diff/Diff.js:86: /** @typedef
{!Array<!{0: number, 1: !Array<string>}>} */
Diff.Diff.Operation?

https://codereview.chromium.org/2729783002/diff/180001/third_party/WebKit/Sou...
File third_party/WebKit/Source/devtools/front_end/source_frame/SourceCodeDiff.js
(right):

https://codereview.chromium.org/2729783002/diff/180001/third_party/WebKit/Sou...
third_party/WebKit/Source/devtools/front_end/source_frame/SourceCodeDiff.js:156:
WorkspaceDiff.workspaceDiff().requestDiff(this._uiSourceCode).then(this._innerUpdate.bind(this));
let's pass this from the outside

https://codereview.chromium.org/2729783002/diff/180001/third_party/WebKit/Sou...
File third_party/WebKit/Source/devtools/front_end/ui/searchableView.css (right):

https://codereview.chromium.org/2729783002/diff/180001/third_party/WebKit/Sou...
third_party/WebKit/Source/devtools/front_end/ui/searchableView.css:36:
.toolbar-search {
wrong rebaseline

https://codereview.chromium.org/2729783002/diff/180001/third_party/WebKit/Sou...
File
third_party/WebKit/Source/devtools/front_end/workspace_diff/WorkspaceDiff.js
(right):

https://codereview.chromium.org/2729783002/diff/180001/third_party/WebKit/Sou...
third_party/WebKit/Source/devtools/front_end/workspace_diff/WorkspaceDiff.js:45:
return this._uiSourceCodeDiffs.get(uiSourceCode);
how does this compile without a cast?

https://codereview.chromium.org/2729783002/diff/180001/third_party/WebKit/Sou...
third_party/WebKit/Source/devtools/front_end/workspace_diff/WorkspaceDiff.js:49:
WorkspaceDiff._UISourceCodeDiff = class extends Common.Object {

WorkspaceDiff.WorkspaceDiff.UISourceCodeDiff

https://codereview.chromium.org/2729783002/diff/180001/third_party/WebKit/Sou...
third_party/WebKit/Source/devtools/front_end/workspace_diff/WorkspaceDiff.js:64:
clearTimeout(this._pendingChanges);
do you really want this logic? In case of continious stream of events about
UISourceCode change, the diff would feel like stale

[einbinder, 2017-03-13 17:47:57]

https://codereview.chromium.org/2729783002/diff/180001/third_party/WebKit/Lay...
File third_party/WebKit/LayoutTests/inspector/sources/source-code-diff.html
(right):

https://codereview.chromium.org/2729783002/diff/180001/third_party/WebKit/Lay...
third_party/WebKit/LayoutTests/inspector/sources/source-code-diff.html:27:
InspectorTest.showUISourceCode(uiSourceCode, () => undefined);
On 2017/03/10 at 01:17:04, lushnikov wrote:
> showUISourceCodePromise

Done.

https://codereview.chromium.org/2729783002/diff/180001/third_party/WebKit/Sou...
File third_party/WebKit/Source/devtools/front_end/ui/searchableView.css (right):

https://codereview.chromium.org/2729783002/diff/180001/third_party/WebKit/Sou...
third_party/WebKit/Source/devtools/front_end/ui/searchableView.css:36:
.toolbar-search {
On 2017/03/10 at 01:17:04, lushnikov wrote:
> wrong rebaseline

Done.

https://codereview.chromium.org/2729783002/diff/180001/third_party/WebKit/Sou...
File
third_party/WebKit/Source/devtools/front_end/workspace_diff/WorkspaceDiff.js
(right):

https://codereview.chromium.org/2729783002/diff/180001/third_party/WebKit/Sou...
third_party/WebKit/Source/devtools/front_end/workspace_diff/WorkspaceDiff.js:45:
return this._uiSourceCodeDiffs.get(uiSourceCode);
On 2017/03/10 at 01:17:04, lushnikov wrote:
> how does this compile without a cast?

Closure trusts you on getting non-nullable values out of maps.

https://codereview.chromium.org/2729783002/diff/180001/third_party/WebKit/Sou...
third_party/WebKit/Source/devtools/front_end/workspace_diff/WorkspaceDiff.js:49:
WorkspaceDiff._UISourceCodeDiff = class extends Common.Object {
On 2017/03/10 at 01:17:04, lushnikov wrote:
> WorkspaceDiff.WorkspaceDiff.UISourceCodeDiff

WorkspaceDiff.WorkspaceDiff._UISourceCodeDiff

https://codereview.chromium.org/2729783002/diff/180001/third_party/WebKit/Sou...
third_party/WebKit/Source/devtools/front_end/workspace_diff/WorkspaceDiff.js:64:
clearTimeout(this._pendingChanges);
On 2017/03/10 at 01:17:04, lushnikov wrote:
> do you really want this logic? In case of continious stream of events about
UISourceCode change, the diff would feel like stale

This is the current behavior. If the user is typing for a long time with no
breaks, we probably shouldn't interrupt them with a potentially expensive diff
operation. And they probably aren't looking at diff.

[lushnikov, 2017-03-13 18:19:14]

https://codereview.chromium.org/2729783002/diff/200001/third_party/WebKit/Sou...
File
third_party/WebKit/Source/devtools/front_end/workspace_diff/WorkspaceDiff.js
(right):

https://codereview.chromium.org/2729783002/diff/200001/third_party/WebKit/Sou...
third_party/WebKit/Source/devtools/front_end/workspace_diff/WorkspaceDiff.js:34:
unsubscribeToDiffChange(uiSourceCode, callback, thisObj) {
unsubscribeFromDiffChange

https://codereview.chromium.org/2729783002/diff/200001/third_party/WebKit/Sou...
third_party/WebKit/Source/devtools/front_end/workspace_diff/WorkspaceDiff.js:49:
WorkspaceDiff.WorkspaceDiff._UISourceCodeDiff = class extends Common.Object {
we don't prefix classes with "_" to show there file-private status; usually,
files under parent classes are considered private.

https://codereview.chromium.org/2729783002/diff/200001/third_party/WebKit/Sou...
third_party/WebKit/Source/devtools/front_end/workspace_diff/WorkspaceDiff.js:89:
var diff = Diff.Diff.lineDiff(baseline.split('\n'), current.split('\n'));
baseline could be null
also, workingCopy might be '' for unloaded uisourcecodes

[einbinder, 2017-03-13 20:46:29]

https://codereview.chromium.org/2729783002/diff/200001/third_party/WebKit/Sou...
File
third_party/WebKit/Source/devtools/front_end/workspace_diff/WorkspaceDiff.js
(right):

https://codereview.chromium.org/2729783002/diff/200001/third_party/WebKit/Sou...
third_party/WebKit/Source/devtools/front_end/workspace_diff/WorkspaceDiff.js:34:
unsubscribeToDiffChange(uiSourceCode, callback, thisObj) {
On 2017/03/13 at 18:19:14, lushnikov wrote:
> unsubscribeFromDiffChange

Done.

https://codereview.chromium.org/2729783002/diff/200001/third_party/WebKit/Sou...
third_party/WebKit/Source/devtools/front_end/workspace_diff/WorkspaceDiff.js:49:
WorkspaceDiff.WorkspaceDiff._UISourceCodeDiff = class extends Common.Object {
On 2017/03/13 at 18:19:14, lushnikov wrote:
> we don't prefix classes with "_" to show there file-private status; usually,
files under parent classes are considered private.

Done.

https://codereview.chromium.org/2729783002/diff/200001/third_party/WebKit/Sou...
third_party/WebKit/Source/devtools/front_end/workspace_diff/WorkspaceDiff.js:89:
var diff = Diff.Diff.lineDiff(baseline.split('\n'), current.split('\n'));
On 2017/03/13 at 18:19:14, lushnikov wrote:
> baseline could be null
> also, workingCopy might be '' for unloaded uisourcecodes

Done.

[einbinder, 2017-03-13 21:11:30]

made the diff nullable

[lushnikov, 2017-03-13 23:02:38]

lgtm

we should rename SourceCodeDiff class into GutterDiff to reduce confusion

https://codereview.chromium.org/2729783002/diff/220001/third_party/WebKit/Sou...
File
third_party/WebKit/Source/devtools/front_end/workspace_diff/WorkspaceDiff.js
(right):

https://codereview.chromium.org/2729783002/diff/220001/third_party/WebKit/Sou...
third_party/WebKit/Source/devtools/front_end/workspace_diff/WorkspaceDiff.js:92:
* @return {!Promise<!Diff.Diff.DiffArray>}
?Diff

[einbinder, 2017-03-14 00:17:30]

The CQ bit was checked by einbinder@chromium.org

[einbinder, 2017-03-14 00:17:31]

https://codereview.chromium.org/2729783002/diff/220001/third_party/WebKit/Sou...
File
third_party/WebKit/Source/devtools/front_end/workspace_diff/WorkspaceDiff.js
(right):

https://codereview.chromium.org/2729783002/diff/220001/third_party/WebKit/Sou...
third_party/WebKit/Source/devtools/front_end/workspace_diff/WorkspaceDiff.js:92:
* @return {!Promise<!Diff.Diff.DiffArray>}
On 2017/03/13 at 23:02:38, lushnikov wrote:
> ?Diff

Done on latest patch set.

[commit-bot: I haz the power, 2017-03-14 00:18:08]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-03-14 00:33:20]

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

[commit-bot: I haz the power, 2017-03-14 00:33:21]

Try jobs failed on following builders:
  linux_android_rel_ng on master.tryserver.chromium.android (JOB_FAILED,
https://build.chromium.org/p/tryserver.chromium.android/builders/linux_androi...)

[lushnikov, 2017-03-15 02:46:50]

The CQ bit was checked by lushnikov@chromium.org

[commit-bot: I haz the power, 2017-03-15 02:47:22]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-03-15 04:25:25]

CQ is committing da patch.

Bot data: {"patchset_id": 240001, "attempt_start_ts": 1489546010069740,
"parent_rev": "ccc25c33b711f0d546fe4edf6b879489ab09cde4", "commit_rev":
"569f345a2ee19b54dc008c3c2011cee9e7405d36"}

[commit-bot: I haz the power, 2017-03-15 04:26:02]

Description was changed from

==========
DevTools: Diff subsystem

This moves the diff computation out of SourceCodeDiff into a new module.
Now the diff can be shared by more than one consumer.

BUG=610061
==========

to

==========
DevTools: Diff subsystem

This moves the diff computation out of SourceCodeDiff into a new module.
Now the diff can be shared by more than one consumer.

BUG=610061

Review-Url: https://codereview.chromium.org/2729783002
Cr-Commit-Position: refs/heads/master@{#456991}
Committed:
https://chromium.googlesource.com/chromium/src/+/569f345a2ee19b54dc008c3c2011...
==========

[commit-bot: I haz the power, 2017-03-15 04:26:03]

Committed patchset #13 (id:240001) as
https://chromium.googlesource.com/chromium/src/+/569f345a2ee19b54dc008c3c2011...