Avoid creating duplicate Range objects when handling misspellings.

third_party/WebKit/Source/core/editing/spellcheck/SpellChecker.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 499 matching lines @@
 
     // Since the text may be quite big chunk it up and adjust to the sentence boundary.
     const int kChunkSize = 16 * 1024;
     int start = fullParagraphToCheck.checkingStart();
     int end = fullParagraphToCheck.checkingEnd();
     start = std::min(start, end);
     end = std::max(start, end);
     const int kNumChunksToCheck = asynchronous ? (end - start + kChunkSize - 1) / (kChunkSize) : 1;
     int currentChunkStart = start;
     if (kNumChunksToCheck == 1 && asynchronous) {
-        EphemeralRange checkRange = fullParagraphToCheck.checkingRange();
+        const EphemeralRange checkRange = fullParagraphToCheck.checkingRange();

[yosin_UTC9, 2015/09/26 04:56:00]

nit: better in another patch.
Sorry, I forgot to add |const|.

[sof, 2015/09/26 06:59:44]

A minor tidyup in any case, but reverted it from this CL.

         markAllMisspellingsAndBadGrammarInRanges(textCheckingOptions, checkRange, checkRange, asynchronous, 0);
         return;
     }
 
     for (int iter = 0; iter < kNumChunksToCheck; ++iter) {
-        EphemeralRange checkRange = expandRangeToSentenceBoundary(fullParagraphToCheck.subrange(currentChunkStart, kChunkSize));
+        const EphemeralRange checkRange = expandRangeToSentenceBoundary(fullParagraphToCheck.subrange(currentChunkStart, kChunkSize));

[yosin_UTC9, 2015/09/26 04:55:59]

nit: better in another patch.
Sorry, I forgot to add |const|.

[sof, 2015/09/26 06:59:43]

Same.

 
         int checkingLength = 0;
         markAllMisspellingsAndBadGrammarInRanges(textCheckingOptions, checkRange, checkRange, asynchronous, iter, &checkingLength);
         currentChunkStart += checkingLength;
     }
 }
 
 void SpellChecker::markAllMisspellingsAndBadGrammarInRanges(TextCheckingTypeMask textCheckingOptions, const EphemeralRange& checkRange, const EphemeralRange& paragraphRange, bool asynchronous, int requestNumber, int* checkingLength)
 {
     TextCheckingParagraph sentenceToCheck(checkRange, paragraphRange);
     if (checkingLength)
         *checkingLength = sentenceToCheck.checkingLength();
 
-    RefPtrWillBeRawPtr<SpellCheckRequest> request = SpellCheckRequest::create(resolveTextCheckingTypeMask(textCheckingOptions), TextCheckingProcessBatch, createRange(checkRange), createRange(paragraphRange), requestNumber);
+    RefPtrWillBeRawPtr<Range> checkRangeObject = createRange(checkRange);
+    RefPtrWillBeRawPtr<Range> paragraphRangeObject = (checkRange == paragraphRange) ? checkRangeObject.get() : createRange(paragraphRange).get();
+    RefPtrWillBeRawPtr<SpellCheckRequest> request = SpellCheckRequest::create(resolveTextCheckingTypeMask(textCheckingOptions), TextCheckingProcessBatch, checkRangeObject, paragraphRangeObject, requestNumber);

[yosin_UTC9, 2015/09/26 04:55:59]

Could you do this in |SpellCheckRequest::create()| instead of here?
It seems all call sites, just two!, |SpellCheckRequest::create()| can use
|EphemeralRange| as parameters:

1. HERE RefPtrWillBeRawPtr<SpellCheckRequest> request =
SpellCheckRequest::create(resolveTextCheckingTypeMask(textCheckingOptions),
TextCheckingProcessBatch, createRange(checkRange), createRange(paragraphRange),
requestNumber);
2. ANOTHER 
    const EphemeralRange range = EphemeralRange::rangeOfContents(element);
    RefPtrWillBeRawPtr<Range> rangeToCheck = Range::create(element.document(),
range.startPosition(), range.endPosition());
m_spellCheckRequester->requestCheckingFor(SpellCheckRequest::create(TextCheckingTypeSpelling
| TextCheckingTypeGrammar, TextCheckingProcessBatch, rangeToCheck,
rangeToCheck));

So, we can make using |Range| object is an implementation detail of 
|SpellCheckRequest|.

[sof, 2015/09/26 06:59:44]

That's well worthwhile, pushed the Range conversion into there instead.

     if (!request)
         return;
 
     if (asynchronous) {
         m_spellCheckRequester->requestCheckingFor(request);
         return;
     }
 
     Vector<TextCheckingResult> results;
     checkTextOfParagraph(textChecker(), sentenceToCheck.text(), resolveTextCheckingTypeMask(textCheckingOptions), results);
@@ skipping 384 matching lines @@
     m_spellCheckRequester->requestCheckingFor(SpellCheckRequest::create(TextCheckingTypeSpelling | TextCheckingTypeGrammar, TextCheckingProcessBatch, rangeToCheck, rangeToCheck));
 }
 
 DEFINE_TRACE(SpellChecker)
 {
     visitor->trace(m_frame);
     visitor->trace(m_spellCheckRequester);
 }
 
 } // namespace blink