Implement a request cache and disble retrieving a sub-region.

chrome/renderer/spellchecker/spellcheck_provider.h

 // 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.
 
 #ifndef CHROME_RENDERER_SPELLCHECKER_SPELLCHECK_PROVIDER_H_
 #define CHROME_RENDERER_SPELLCHECKER_SPELLCHECK_PROVIDER_H_
 #pragma once
 
 #include <vector>
 
@@ skipping 67 matching lines @@
       const WebKit::WebString& word) OVERRIDE;
 
 #if !defined(OS_MACOSX)
   void OnRespondSpellingService(
       int identifier,
       int offset,
       bool succeeded,
       const string16& text,
       const std::vector<SpellCheckResult>& results);
 
-  // Returns whether |text| has word characters after |index|, i.e. whether a
-  // spellchecker needs to check this text.
-  bool HasWordCharacters(const string16& text, int index) const;
-
-  // Returns a line that should be sent to a browser to spellcheck it.
-  bool GetRequestLine(const string16& text,
-                      string16* request,
-                      int* offset) const;
+  // Returns whether |text| has word characters, i.e. whether a spellchecker
+  // needs to check this text.
+  bool HasWordCharacters(const WebKit::WebString& text, int index) const;
 #endif
 #if defined(OS_MACOSX)
   void OnAdvanceToNextMisspelling();
   void OnRespondTextCheck(
       int identifier,
       int tag,
       const std::vector<SpellCheckResult>& results);
   void OnToggleSpellPanel(bool is_currently_visible);
 #endif
   void OnToggleSpellCheck();
 
   // Initializes the document_tag_ member if necessary.
   void EnsureDocumentTag();
 
   // Holds ongoing spellchecking operations, assigns IDs for the IPC routing.
   WebTextCheckCompletions text_check_completions_;
 
 #if !defined(OS_MACOSX)
-  // The last line sent to the browser process to spellcheck it.
-  string16 last_line_;
+  // The last text sent to the browser process to spellcheck it and its
+  // spellchecking results.
+  string16 last_request_;
+  WebKit::WebVector<WebKit::WebTextCheckingResult> last_results_;
 #endif
 
 #if defined(OS_MACOSX)
   // True if the current RenderView has been assigned a document tag.
   bool has_document_tag_;
 #endif
 
   int document_tag_;
 
   // True if the browser is showing the spelling panel for us.
   bool spelling_panel_visible_;
 
   // The ChromeContentRendererClient used to access the SpellChecker.
   // Weak reference.
   chrome::ChromeContentRendererClient* chrome_content_renderer_client_;
 
   DISALLOW_COPY_AND_ASSIGN(SpellCheckProvider);
 };
 
 #endif  // CHROME_RENDERER_SPELLCHECKER_SPELLCHECK_PROVIDER_H_