Currently, `AutoStyleCacheArray` has style information of all 19 styles.
However, its element type, `StyleCache` has `nsString` instance. Therefore,
the initializing cost is not reasonable since in most cases most of the
`StyleCache` instances are not used actually.
This patch makes `HTMLEditor::GetInlineStyles()` append elements only for
applied styles and `HTMLEditor::ReapplyCachedStyles()` look for current
value from an instance with new `IndexOf()` method. Therefore, this patch
may make slower if a lot of styles are applied. However, we can expect that
it's rare case.
Differential Revision: https://phabricator.services.mozilla.com/D61262
--HG--
extra : moz-landing-system : lando
Previously, I added `Selection::mCachedRange` to save allocation cost of
`nsRange`. However, with the previous patch, we don't need the hack anymore
since ranges removed by `Selection::RemoveAllRanges()` are always kept in
the global cache of `nsRange`. Therefore, we can remove the ugly hack right
now.
Differential Revision: https://phabricator.services.mozilla.com/D61239
--HG--
extra : moz-landing-system : lando
`nsRange` instances are allocated a lot in the heap especially by editor and
spellchecker. The allocation cost is too bad for benchmarks. Therefore,
we should reuse released instances as far as possible. For managing it in
static factory methods of `nsRange`, we need to hide `nsRange` constructor.
Differential Revision: https://phabricator.services.mozilla.com/D61237
--HG--
extra : moz-landing-system : lando
* `nsIHTMLEditor.removeAllInlineProperties`
* `nsIHTMLEditor.increaseFontSize`
* `nsIHTMLEditor.decreaseFontSize`
* `nsIHTMLEditor.setParagraphFormat`
* `nsIHTMLEditor.getBackgroundColorState`
* `nsIHTMLEditor.indent`
* `nsIHTMLEditor.align`
* `nsIEditorStyleSheets.replaceOverrideStyleSheet`
* `nsITableEditor.selectBlockOfCells`
These methods are not used by any Gecko products including comm-central and
BlueGriffon so that we should remove them. Note that only
`HTMLEditor::GetBackgroundColorState()` is used internally so that we need to
keep it as a public method of `HTMLEditor`.
Differential Revision: https://phabricator.services.mozilla.com/D61139
--HG--
extra : moz-landing-system : lando
`DragEvent::GetRangeParentContentAndOffset()` may return `nullptr`. Previously,
it was checked and returned `NS_ERROR_FAILURE` before landing bug 1610264.
This patch adds the null check which was accidentally removed.
Differential Revision: https://phabricator.services.mozilla.com/D61208
--HG--
extra : moz-landing-system : lando
`drop` event shouldn't be fired when drop target does not accept the data
at last `dragover` handling.
This patch makes `synthesizePlainDragAndDrop()` stop dispatching `drop` event
if last `dragover` event's `dataTransfer.dropEffect` is `none`. In strictly
speaking, it should refer `nsIDragSession::canDrop`. However, the value is
unstable only on Linux. The reason must be that only GTK widget manages
`canDrop` state by itself. Therefore, this patch directly uses the
`dataTransfer.dropEffect` value instead.
Differential Revision: https://phabricator.services.mozilla.com/D60476
--HG--
extra : moz-landing-system : lando
Currently, editor does not consume `dragenter`, `dragover` nor `drop` event if
`EditorEventListener::CanDrop()` returns false. Then,
`EventStateManager::PostHandleEvent()` does not modify current drag session
with given drop effect value. Therefore, it does not make sense that
`EditorEventListener` modifies modify drop effect of `DragEvent::mDataTransfer`
only with calling `Event::StopPropagation()`.
This patch makes `EditorEventListener` consume `eDragEnter`, `eDragOver` and
`eDrop` events unless drop target is not managed by the editor (i.e., when
drop target is non-editable nodes in HTML editor, or the editor is a part of
`<input type="file">`).
Then, `EditorEventListenr::DragOver()` and `EditorEventListener::Drop()`
become really similar. Therefore, this patch also merges them. Their
differences are only:
* Only `Drop()` calls `CleanupDragDropCaret()` first.
* The main purpose code (calling `TextEditor::OnDrop()` from `Drop()` and
modifying drop effect and caret from `DragOver()`)
Differential Revision: https://phabricator.services.mozilla.com/D60475
--HG--
extra : moz-landing-system : lando
For preparing to remove `nsIPlaintextEditor` interface, this patch moves
all of them to `nsIEditor`, but for avoiding bustage in comm-central, makes
`nsIPlaintextEditor` inherit `nsIEditor` for now (i.e., even with this patch,
script can access old `nsIPlaintextEditor` members with the interface.
In C++ code, this patch moves `SetWrapColumn()`, `InsertTextAsAction()`,
`InsertTextAsSubAction()` and `InsertLineBreakAsSubAction()` because
they do common things between `TextEditor` and `HTMLEditor`. On the other
hand, this does not move `TextEditor::GetTextLength()` because it's designed
only for `TextEditor`.
Differential Revision: https://phabricator.services.mozilla.com/D60820
--HG--
rename : editor/libeditor/tests/test_nsIPlaintextEditor_insertLineBreak.html => editor/libeditor/tests/test_nsIEditor_insertLineBreak.html
extra : moz-landing-system : lando
* getAttributeValue
* cloneAttribute
* splitNode
* joinNodes
* markNodeDirty
* removeEditorObserver
are not used from script. Therefore, we can get rid of them from `nsIEditor`.
However, `EditorBase::GetAttributeValue()` is referred by
`HTMLEditor::CopyCellBackgroundColor()` and it's just a wrapper of
`Element::GetAttr()`. Therefore, this patch makes
`HTMLEditor::CopyCellBackgroundColor()` use `Element::GetAttr()` directly.
And also `EditorBase::MarkNodeDirty()` is used from some friend classes.
Therefore, this patch redesigns it as `MarkElementDirty()` and make all of
them check whether the method call destroys the editor.
Differential Revision: https://phabricator.services.mozilla.com/D60796
--HG--
extra : moz-landing-system : lando
Current `nsIHTMLEditor::GetSelectedElement()` just checks whether the
found element is followed by `<br>` element or not. However, following
element may start with `<br>` element and if there is end of the range,
`PostContentIterator` does not list up the `<br>` element.
Therefore, it should check whether the found element is followed by
`<br>` element which is starts the next sibling element too.
Differential Revision: https://phabricator.services.mozilla.com/D60385
--HG--
extra : moz-landing-system : lando
This was done by:
This was done by applying:
```
diff --git a/python/mozbuild/mozbuild/code-analysis/mach_commands.py b/python/mozbuild/mozbuild/code-analysis/mach_commands.py
index 789affde7bbf..fe33c4c7d4d1 100644
--- a/python/mozbuild/mozbuild/code-analysis/mach_commands.py
+++ b/python/mozbuild/mozbuild/code-analysis/mach_commands.py
@@ -2007,7 +2007,7 @@ class StaticAnalysis(MachCommandBase):
from subprocess import Popen, PIPE, check_output, CalledProcessError
diff_process = Popen(self._get_clang_format_diff_command(commit), stdout=PIPE)
- args = [sys.executable, clang_format_diff, "-p1", "-binary=%s" % clang_format]
+ args = [sys.executable, clang_format_diff, "-p1", "-binary=%s" % clang_format, '-sort-includes']
if not output_file:
args.append("-i")
```
Then running `./mach clang-format -c <commit-hash>`
Then undoing that patch.
Then running check_spidermonkey_style.py --fixup
Then running `./mach clang-format`
I had to fix four things:
* I needed to move <utility> back down in GuardObjects.h because I was hitting
obscure problems with our system include wrappers like this:
0:03.94 /usr/include/stdlib.h:550:14: error: exception specification in declaration does not match previous declaration
0:03.94 extern void *realloc (void *__ptr, size_t __size)
0:03.94 ^
0:03.94 /home/emilio/src/moz/gecko-2/obj-debug/dist/include/malloc_decls.h:53:1: note: previous declaration is here
0:03.94 MALLOC_DECL(realloc, void*, void*, size_t)
0:03.94 ^
0:03.94 /home/emilio/src/moz/gecko-2/obj-debug/dist/include/mozilla/mozalloc.h:22:32: note: expanded from macro 'MALLOC_DECL'
0:03.94 MOZ_MEMORY_API return_type name##_impl(__VA_ARGS__);
0:03.94 ^
0:03.94 <scratch space>:178:1: note: expanded from here
0:03.94 realloc_impl
0:03.94 ^
0:03.94 /home/emilio/src/moz/gecko-2/obj-debug/dist/include/mozmemory_wrap.h:142:41: note: expanded from macro 'realloc_impl'
0:03.94 #define realloc_impl mozmem_malloc_impl(realloc)
Which I really didn't feel like digging into.
* I had to restore the order of TrustOverrideUtils.h and related files in nss
because the .inc files depend on TrustOverrideUtils.h being included earlier.
* I had to add a missing include to RollingNumber.h
* Also had to partially restore include order in JsepSessionImpl.cpp to avoid
some -WError issues due to some static inline functions being defined in a
header but not used in the rest of the compilation unit.
Differential Revision: https://phabricator.services.mozilla.com/D60327
--HG--
extra : moz-landing-system : lando
rg -l 'mozilla/Move.h' | xargs sed -i 's/#include "mozilla\/Move.h"/#include <utility>/g'
Further manual fixups and cleanups to the include order incoming.
Differential Revision: https://phabricator.services.mozilla.com/D60323
--HG--
extra : moz-landing-system : lando
In C++ code, `DataTransfer::GetTypes()` are used for checking whether the
`DataTransfer` instance has specific type `DataTransferItem` or not. Therefore,
it does not make sense to retrieve all item types nor compare some types
looking for with the retrieved item types.
This patch adds `DataTransfer::HasType()` and `DataTransfer::HasFile()` for
the current C++ users. They don't take `CallerType` since all C++ users use
`GetTypes()` as `CallertType::System`. And they just call a corresponding
method of `DataTransferItemList`.
Then, `DataTransferItemList` methods compares given type with every items
simply.
Note that this patch moves `DataTransfer::GetTypes()` to `DataTransferItemList`
too because new methods and `GetTypes()` should be maintained at every logic
changes.
The reason why there is no `DataTransfer::HasAnyOfTypes()` method is,
`DataTransfer.h` cannot include `DataTransferItemList.h` due to their
dependency but parameter pack requires inline methods.
Differential Revision: https://phabricator.services.mozilla.com/D60387
--HG--
extra : moz-landing-system : lando
When file is dropped on `contenteditable` element, the data is `BlobImpl`
instance in e10s mode. Then, editor tries to insert asynchronously with its
`BlobReader`. However, currently, `BlobReader` does not have a reference of
`DataTransfer` object for setting `beforeinput` event and `input` event.
Therefore, when you drop file into `contenteditable` element on debug build,
you see hitting `MOZ_ASSERT` because of unexpected null `DataTransfer` object.
This patch makes it store `DataTransfer` object for both `beforeinput` event
and `input` event, and dispatch `beforeinput` event only when it hasn't been
dispatched yet (i.e., not dispatched before it's created). The case shouldn't
occur, but let's have the fallback path in release builds for avoiding
inconvenience of our users.
Differential Revision: https://phabricator.services.mozilla.com/D60238
--HG--
extra : moz-landing-system : lando
It removes a script blocker. Therefore, although it depends on the caller
whether it causes running script or not. However, we should mark it as
`MOZ_CAN_RUN_SCRIPT` for safer code.
It's called only by the destructor of `nsAutoCauseReflowNotifier`. Therefore,
this patch also marks its constructor as `MOZ_CAN_RUN_SCRIPT` for making
each creator method marked as `MOZ_CAN_RUN_SCRIPT` or
`MOZ_CAN_RUN_SCRIPT_BOUNDARY`.
Most of the creators is mutation listener methods. However, `PresShell`
does nothing after destroying `nsAutoCauseReflowNotifier`. Therefore,
this patch does not change the callers in MutationObserver.cpp to use
`RefPtr<PresShell>` at calling them because changing it may cause performance
regression.
Perhaps, we should create another methods of `WillCauseReflow()` and
`DidCauseReflow()` to avoid unnecessary `MOZ_CAN_RUN_SCRIPT` marking.
However, I'm not sure whether most callers may run script or not because
of outside of my knowledge.
Differential Revision: https://phabricator.services.mozilla.com/D55805
--HG--
extra : moz-landing-system : lando
`UIEvent::GetRangeParent()` retrieves `nsIContent` instance but it needs to
return `already_AddRefed<nsINode>` because of a WebIDL method. However,
`nsIContent` is better type in C++ code. Therefore, this patch renames it
to `UIEvent::GetRangeParentContent()` and makes new `UIEvent::GetRangeParent()`
and just call it.
Additionally, some callers call `UIEvent::RangeOffset()` too, but that means
that they compute same things twice because both of them use
`nsLayoutUtils::GetContainerAndOffsetAtEvent()` with same input arguments.
Thus, `UIEvent::GetRangeParentContent()` should also return offset with optional
out argument. (Note that this does not make `RangeOffset()` use
`GetRangeParentContent()` because using out parameter for range parent causes
unnecessary computation cost for `RangeOffset()`.)
Therefore, finally, `UIEvent::GetRangeParentContent()` becomes also an alias of
raw method `UIEvent::GetRangeParentContentAndOffset()` which also returns offset
with out argument.
Differential Revision: https://phabricator.services.mozilla.com/D60095
--HG--
extra : moz-landing-system : lando
Instead, subclass nsTextControlFrame. This simplifies the code and avoids
correctness issues.
I kept the localization functionality though it is not spec compliant. But I
filed a bug to remove it in a followup.
Differential Revision: https://phabricator.services.mozilla.com/D57193
--HG--
extra : moz-landing-system : lando
Instead, subclass nsTextControlFrame. This simplifies the code and avoids
correctness issues.
I kept the localization functionality though it is not spec compliant. But I
filed a bug to remove it in a followup.
Differential Revision: https://phabricator.services.mozilla.com/D57193
--HG--
extra : moz-landing-system : lando
`AutoEditActionDataSetter` is created in the stack when editor's public method
is called and that guarantees lifetime of global objects in editor such as
editor itself, selection controller, etc.
The dispatcher of `beforeinput` event returns `NS_ERROR_EDITOR_ACTION_CANCELED`
if an event is actually dispatched but canceled. The reason why it's an error
is, editor code must stop handling anything when any methods return error.
So, returning an error code is reasonable in editor module. But when it's
filtered by `EditorBase::ToGenericNSResult()` at return statement of public
methods, it's converted to `NS_SUCCESS_DOM_NO_OPERATION`. This avoids throwing
new exception, but editor class users in C++ can distinguish whether each edit
action is canceled or handled. The reason why we should not throw new
exception from XPCOM API is, without taking care of each caller may break some
our UI (especially for avoiding to break comm-central). Therefore, this patch
does not make XPCOM methods return error code when `beforeinput` event is
canceled.
In most cases, immediately after creating `AutoEditActionDataSetter` is good
timing to dispatch `beforeinput` event since editor has not touched the DOM
yet. If `beforeinput` requires `data` or `dataTransfer`, methods need to
dispatch `beforeinput` event after that. Alhtough this is not a good thing
from point of view of consistency of the code. However, I have no better
idea.
Note 1: Our implementation does NOT conform to the spec about event order
between `keypress` and `beforeinput` (dispatching `beforeinput` event after
`keypress` event). However, we follow all other browsers' behavior so that it
must be safe and the spec should be updated for backward compatibility.
Spec issue: https://github.com/w3c/uievents/issues/220
Note 2: Our implementation does NOT conform to the spec about event order
between `compositionupdate` and `beforeinput`. Our behavior is same as
Safari, but different from Chrome. This might cause web-compat issues.
However, our behavior does make sense from point of view of consistency of
event spec. Additionally, at both `compositionupdate` and `beforeinput`,
composition string in editor has not been modified yet. Therefore, this
may not cause web-compat issues (and I hope so).
Spec issue: https://github.com/w3c/input-events/issues/49
Note that this patch makes editor detect bugs that `beforeinput` event hasn't
been handled yet when it dispatches `input` event or modifying `data` and
`dataTransfer` value are modified after dispatching `beforeinput` event with
`MOZ_ASSERT`s.
Differential Revision: https://phabricator.services.mozilla.com/D58127
--HG--
extra : moz-landing-system : lando
This patch makes `nsContentUtils::DispatchInputEvent()` dispatch `beforeinput`
event too. And also adds `onbeforeinput` event handler which is really
important for feature detection (although Chrome has not implemented this
attribute yet: https://bugs.chromium.org/p/chromium/issues/detail?id=947408).
However, we don't implement `InputEvent.getTargetRanges()` in this bug and
implementing `beforeinput` event may hit bugs of some web apps. Therefore,
this patch disables `beforeinput` event by default even in Nightly channel.
Differential Revision: https://phabricator.services.mozilla.com/D58125
--HG--
extra : moz-landing-system : lando
Some HTML editor command classes call `*AsAction()` methods multiple times.
That causes that user needs multiple undo/redo for a command and one command
causes multiple "input" events. For both compatibility with the other
browsers and making "beforeinput" cancelable, they should call `*AsAction()`
once. Instead, `HTMLEditor` should handle related element deletion.
This patch makes `HTMLEditor::RemoveInlinePropertyInternal()` remove multiple
elements if its caller allows, and `HTMLEditor::SetInlinePropertyAsAction()`
call `RemoveInlinePropertyInternal()` in some cases.
According to comm-central and BlueGriffon, we can make
`HTMLEditor::RemoveInlineProperty()` also removes the related methods
automatically because comm-central does same thing from script and BlueGriffon
does not use this. However, we cannot do that for
`HTMLEditor::SetInlineProperty()` because BlueGriffon may call it with any
HTML5 elements and does not expect removing elements in same block at that
time. If we needed to reduce the overhead of comm-central, we could change
only `RemoveInlineProperty()`, but it would make these APIs behavior
inconsistent.
Differential Revision: https://phabricator.services.mozilla.com/D58124
--HG--
extra : moz-landing-system : lando
This patch adds a lot of `beforeinput` event tests into existing mochitests
which test `input` events. But this does not add tests of canceling
`beforeinput` event because it requires really complicated path until
implementing `beforeinput` actually.
Note that `beforeinput` event is not fired with `Document.execCommand()`.
Therefore, this patch does not add WPT for testing `beforeinput` event.
And unfortunately, WPT cannot test most cases of the new tests.
Differential Revision: https://phabricator.services.mozilla.com/D58123
--HG--
extra : moz-landing-system : lando
`AutoEditActionDataSetter` is created in the stack when editor's public method
is called and that guarantees lifetime of global objects in editor such as
editor itself, selection controller, etc.
The dispatcher of `beforeinput` event returns `NS_ERROR_EDITOR_ACTION_CANCELED`
if an event is actually dispatched but canceled. The reason why it's an error
is, editor code must stop handling anything when any methods return error.
So, returning an error code is reasonable in editor module. But when it's
filtered by `EditorBase::ToGenericNSResult()` at return statement of public
methods, it's converted to `NS_SUCCESS_DOM_NO_OPERATION`. This avoids throwing
new exception, but editor class users in C++ can distinguish whether each edit
action is canceled or handled. The reason why we should not throw new
exception from XPCOM API is, without taking care of each caller may break some
our UI (especially for avoiding to break comm-central). Therefore, this patch
does not make XPCOM methods return error code when `beforeinput` event is
canceled.
In most cases, immediately after creating `AutoEditActionDataSetter` is good
timing to dispatch `beforeinput` event since editor has not touched the DOM
yet. If `beforeinput` requires `data` or `dataTransfer`, methods need to
dispatch `beforeinput` event after that. Alhtough this is not a good thing
from point of view of consistency of the code. However, I have no better
idea.
Note 1: Our implementation does NOT conform to the spec about event order
between `keypress` and `beforeinput` (dispatching `beforeinput` event after
`keypress` event). However, we follow all other browsers' behavior so that it
must be safe and the spec should be updated for backward compatibility.
Spec issue: https://github.com/w3c/uievents/issues/220
Note 2: Our implementation does NOT conform to the spec about event order
between `compositionupdate` and `beforeinput`. Our behavior is same as
Safari, but different from Chrome. This might cause web-compat issues.
However, our behavior does make sense from point of view of consistency of
event spec. Additionally, at both `compositionupdate` and `beforeinput`,
composition string in editor has not been modified yet. Therefore, this
may not cause web-compat issues (and I hope so).
Spec issue: https://github.com/w3c/input-events/issues/49
Note that this patch makes editor detect bugs that `beforeinput` event hasn't
been handled yet when it dispatches `input` event or modifying `data` and
`dataTransfer` value are modified after dispatching `beforeinput` event with
`MOZ_ASSERT`s.
Differential Revision: https://phabricator.services.mozilla.com/D58127
--HG--
extra : moz-landing-system : lando
This patch makes `nsContentUtils::DispatchInputEvent()` dispatch `beforeinput`
event too. And also adds `onbeforeinput` event handler which is really
important for feature detection (although Chrome has not implemented this
attribute yet: https://bugs.chromium.org/p/chromium/issues/detail?id=947408).
However, we don't implement `InputEvent.getTargetRanges()` in this bug and
implementing `beforeinput` event may hit bugs of some web apps. Therefore,
this patch disables `beforeinput` event by default even in Nightly channel.
Differential Revision: https://phabricator.services.mozilla.com/D58125
--HG--
extra : moz-landing-system : lando
Some HTML editor command classes call `*AsAction()` methods multiple times.
That causes that user needs multiple undo/redo for a command and one command
causes multiple "input" events. For both compatibility with the other
browsers and making "beforeinput" cancelable, they should call `*AsAction()`
once. Instead, `HTMLEditor` should handle related element deletion.
This patch makes `HTMLEditor::RemoveInlinePropertyInternal()` remove multiple
elements if its caller allows, and `HTMLEditor::SetInlinePropertyAsAction()`
call `RemoveInlinePropertyInternal()` in some cases.
According to comm-central and BlueGriffon, we can make
`HTMLEditor::RemoveInlineProperty()` also removes the related methods
automatically because comm-central does same thing from script and BlueGriffon
does not use this. However, we cannot do that for
`HTMLEditor::SetInlineProperty()` because BlueGriffon may call it with any
HTML5 elements and does not expect removing elements in same block at that
time. If we needed to reduce the overhead of comm-central, we could change
only `RemoveInlineProperty()`, but it would make these APIs behavior
inconsistent.
Differential Revision: https://phabricator.services.mozilla.com/D58124
--HG--
extra : moz-landing-system : lando
This patch adds a lot of `beforeinput` event tests into existing mochitests
which test `input` events. But this does not add tests of canceling
`beforeinput` event because it requires really complicated path until
implementing `beforeinput` actually.
Note that `beforeinput` event is not fired with `Document.execCommand()`.
Therefore, this patch does not add WPT for testing `beforeinput` event.
And unfortunately, WPT cannot test most cases of the new tests.
Differential Revision: https://phabricator.services.mozilla.com/D58123
--HG--
extra : moz-landing-system : lando
Now that we have UTF8String in the WebIDL, we can remove quite a few of the
conversions. Do that, and lift the remaining string conversions up as needed.
Also deindent Servo_ComputeColor while touching it.
Most of the remaining copies are because either bug 1606994, or because they're
WebIDL attributes that we still need to serialize back as UTF-16 (bug 1606995).
Differential Revision: https://phabricator.services.mozilla.com/D58687
--HG--
extra : moz-landing-system : lando
In particular, the ones where we transcode unconditionally atm (property names
and such).
There are others like cssText getters and setters which are a bit harder,
because I either need to rewrite all our serialization code to work with UTF8
(which is fine, but a lot of work), or teach webidl to have a setter that takes
UTF8String as input but returns DOMString as output (which is at best hacky).
Differential Revision: https://phabricator.services.mozilla.com/D58631
--HG--
extra : moz-landing-system : lando
test_password_per_word_operation.html uses magic number to consider
click point in `<input>` element. However, that causes permanent
failure on Ubuntu 18.04. Ideally, the click positions should be
computed dynamically. Therefore, this patch makes it use rect of
anonymous `<div>` element and rect of its child text node which can
be computed with `Range.getBoundingClientRect()`.
Differential Revision: https://phabricator.services.mozilla.com/D58193
--HG--
extra : moz-landing-system : lando
Most tests which use these APIs don't want to distinguish difference of
linebreaks (i.e., CRLF vs. CR vs. LF). And also most tests don't want to
check prefix and postfix of HTML data in clipboard on Windows.
Therefore, this patch makes them compare clipboard data with expected string
smarter. Every linebreak in clipboard data are treated as LF. Expected
HTML data is wrapped with `<html>`, `<body>` and comment nodes only on
Windows at comparing with clipboard data.
Differential Revision: https://phabricator.services.mozilla.com/D57963
--HG--
extra : moz-landing-system : lando
User can move DnD between different 2 editors. Then, deleting selection in
drag source editor should be handled by the drag source editor rather than
drop target editor. Therefore, `TextEditor::OnDrop()` should look for
editor instance for drag source node and call is "deleteByDrag" handler.
Differential Revision: https://phabricator.services.mozilla.com/D57449
--HG--
extra : moz-landing-system : lando
