Spellchecking should not be cancelled if editing is done in between

chrome/renderer/spellchecker/spellcheck_provider.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/renderer/spellchecker/spellcheck_provider.h"
 
 #include "base/command_line.h"
 #include "base/metrics/histogram.h"
+#include "base/strings/utf_string_conversions.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/spellcheck_marker.h"
 #include "chrome/common/spellcheck_messages.h"
 #include "chrome/common/spellcheck_result.h"
 #include "chrome/renderer/spellchecker/spellcheck.h"
 #include "chrome/renderer/spellchecker/spellcheck_language.h"
 #include "content/public/renderer/render_view.h"
 #include "third_party/WebKit/public/platform/WebVector.h"
 #include "third_party/WebKit/public/web/WebDocument.h"
 #include "third_party/WebKit/public/web/WebElement.h"
@@ skipping 289 matching lines @@
   // the user editing the text.
   base::string16 request(text);
   size_t text_length = request.length();
   if (text_length >= last_length &&
       !request.compare(0, last_length, last_request_)) {
     if (text_length == last_length || !HasWordCharacters(text, last_length)) {
       completion->didFinishCheckingText(last_results_);
       return true;
     }
     int code = 0;
-    int length = static_cast<int>(text_length);
-    U16_PREV(text.data(), 0, length, code);
+    base::string16 requested_text = text + base::UTF8ToUTF16(" ");
+    int length = static_cast<int>(requested_text.length());
+    U16_PREV(requested_text.data(), 0, length, code);
     UErrorCode error = U_ZERO_ERROR;
     if (uscript_getScript(code, &error) != USCRIPT_COMMON) {
       completion->didCancelCheckingText();
       return true;
     }
   }
   // Create a subset of the cached results and return it if the given text is a
   // substring of the cached text.
   if (text_length < last_length &&
       !last_request_.compare(0, text_length, request)) {
@@ skipping 12 matching lines @@
         results[i].length = last_results_[i].length;
         results[i].replacement = last_results_[i].replacement;
       }
       completion->didFinishCheckingText(results);
       return true;
     }
   }
 
   return false;
 }