Stop using VisiblePosition in HotModeSpellCheckRequester

This patch changes HotModeSpellCheckRequester to use uncanonical versions
of PreviousWordPosition and EndOfWord to reduce usage of VisiblePosition.

Bug: 657237
Change-Id: I26428ede826bc63ee76af02ace14a8bf43d69e25
Reviewed-on: https://chromium-review.googlesource.com/c/1313839Reviewed-by: Yoshifumi Inoue <yosin@chromium.org>
Reviewed-by: Yoichi Osato <yoichio@chromium.org>
Commit-Queue: Xiaocheng Hu <xiaochengh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#604834}

third_party/blink/renderer/core/editing/spellcheck/hot_mode_spell_check_requester.cc

@@ -27,16 +27,15 @@ const int kHotModeCheckAllThreshold = 128;
 const int kHotModeChunkSize = 1024;
 
 EphemeralRange AdjacentWordIfExists(const Position& pos) {
-  const VisiblePosition& visible_pos = CreateVisiblePosition(pos);
-  const VisiblePosition& word_start = PreviousWordPosition(visible_pos);
+  const Position word_start = PreviousWordPosition(pos).GetPosition();
   if (word_start.IsNull())
     return EphemeralRange();
-  const VisiblePosition& word_end = EndOfWord(word_start);
+  const Position word_end = EndOfWordPosition(word_start);
   if (word_end.IsNull())
     return EphemeralRange();
-  if (ComparePositions(visible_pos, word_end) > 0)
+  if (ComparePositions(pos, word_end) > 0)
     return EphemeralRange();
-  return EphemeralRange(word_start.DeepEquivalent(), word_end.DeepEquivalent());
+  return EphemeralRange(word_start, word_end);
 }
 
 EphemeralRange CurrentWordIfTypingInPartialWord(const Element& editable) {

third_party/blink/renderer/core/editing/visible_units.h

@@ -128,9 +128,10 @@ StartOfWord(const VisiblePositionInFlatTree&,
             EWordSide = kNextWordIfOnBoundary);
 CORE_EXPORT VisiblePosition EndOfWord(const VisiblePosition&,
                                       EWordSide = kNextWordIfOnBoundary);
+CORE_EXPORT Position EndOfWordPosition(const Position&,
+                                       EWordSide = kNextWordIfOnBoundary);
 CORE_EXPORT PositionInFlatTree
-EndOfWordPosition(const VisiblePositionInFlatTree&,
-                  EWordSide = kNextWordIfOnBoundary);
+EndOfWordPosition(const PositionInFlatTree&, EWordSide = kNextWordIfOnBoundary);
 CORE_EXPORT VisiblePositionInFlatTree
 EndOfWord(const VisiblePositionInFlatTree&, EWordSide = kNextWordIfOnBoundary);
 // TODO(crbug.com/657237): Change all callers to use non-canonical versions.