Stop SpellCheckProvider from deciding typing progress

components/spellcheck/renderer/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 COMPONENTS_SPELLCHECK_RENDERER_SPELLCHECK_PROVIDER_H_
 #define COMPONENTS_SPELLCHECK_RENDERER_SPELLCHECK_PROVIDER_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 24 matching lines @@
       public content::RenderViewObserverTracker<SpellCheckProvider>,
       public blink::WebSpellCheckClient {
  public:
   using WebTextCheckCompletions = IDMap<blink::WebTextCheckingCompletion*>;
 
   SpellCheckProvider(content::RenderView* render_view,
                      SpellCheck* spellcheck);
   ~SpellCheckProvider() override;
 
   // Requests async spell and grammar checker to the platform text
-  // checker, which is available on the browser process.
+  // checker, which is available on the browser process. The function does not
+  // have special handling for partial words, as Blink guarantees that no
+  // request is made when typing in the middle of a word.
   void RequestTextChecking(
       const base::string16& text,
       blink::WebTextCheckingCompletion* completion,
       const std::vector<SpellCheckMarker>& markers);
 
   // The number of ongoing IPC requests.
   size_t pending_text_request_size() const {
     return text_check_completions_.size();
   }
 
@@ skipping 70 matching lines @@
   // True if the browser is showing the spelling panel for us.
   bool spelling_panel_visible_;
 
   // Weak pointer to shared (per RenderView) spellcheck data.
   SpellCheck* spellcheck_;
 
   DISALLOW_COPY_AND_ASSIGN(SpellCheckProvider);
 };
 
 #endif  // COMPONENTS_SPELLCHECK_RENDERER_SPELLCHECK_PROVIDER_H_