Make SpellCheckPanel compiled and used only on Mac

components/spellcheck/common/spellcheck_messages.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.
 
 // IPC messages for spellcheck.
 // Multiply-included message file, hence no include guard.
 
 #include <stdint.h>
 
 #include "components/spellcheck/common/spellcheck_bdict_language.h"
@@ skipping 45 matching lines @@
 // If the service is not available, the 4th parameter should be false and the
 // 5th parameter should contain the requested sentence.
 IPC_MESSAGE_ROUTED4(SpellCheckMsg_RespondSpellingService,
                     int /* request identifier given by WebKit */,
                     bool /* succeeded calling service */,
                     base::string16 /* sentence */,
                     std::vector<SpellCheckResult>)
 #endif
 
 #if BUILDFLAG(USE_BROWSER_SPELLCHECKER)
-// This message tells the renderer to advance to the next misspelling. It is
-// sent when the user clicks the "Find Next" button on the spelling panel.
-IPC_MESSAGE_ROUTED0(SpellCheckMsg_AdvanceToNextMisspelling)
-
 // Sends when NSSpellChecker finishes checking text received by a preceding
 // SpellCheckHostMsg_RequestTextCheck message.
 IPC_MESSAGE_ROUTED3(SpellCheckMsg_RespondTextCheck,
                     int /* request identifier given by WebKit */,
                     base::string16 /* sentence */,
                     std::vector<SpellCheckResult>)
+#endif
+
+#if BUILDFLAG(HAS_SPELLCHECK_PANEL)
+// This message tells the renderer to advance to the next misspelling. It is
+// sent when the user clicks the "Find Next" button on the spelling panel.
+IPC_MESSAGE_ROUTED0(SpellCheckMsg_AdvanceToNextMisspelling)
 
 IPC_MESSAGE_ROUTED1(SpellCheckMsg_ToggleSpellPanel, bool)
 #endif
 
 // Messages sent from the renderer to the browser.
 
 // The renderer has tried to spell check a word, but couldn't because no
 // dictionary was available to load. Request that the browser find an
 // appropriate dictionary and return it.
 IPC_MESSAGE_CONTROL0(SpellCheckHostMsg_RequestDictionary)
 
 // Tracks spell checking occurrence to collect histogram.
 IPC_MESSAGE_ROUTED2(SpellCheckHostMsg_NotifyChecked,
                     base::string16 /* word */,
                     bool /* true if checked word is misspelled */)
 
 #if !BUILDFLAG(USE_BROWSER_SPELLCHECKER)
 // Asks the Spelling service to check text. When the service finishes checking
 // the input text, it sends a SpellingCheckMsg_RespondSpellingService with
 // text-check results.
 IPC_MESSAGE_CONTROL3(SpellCheckHostMsg_CallSpellingService,
                      int /* route_id for response */,
                      int /* request identifier given by WebKit */,
                      base::string16 /* sentence */)
 #endif
 
 #if BUILDFLAG(USE_BROWSER_SPELLCHECKER)
-// Tells the browser to display or not display the SpellingPanel
-IPC_MESSAGE_ROUTED1(SpellCheckHostMsg_ShowSpellingPanel,
-                    bool /* if true, then show it, otherwise hide it*/)
-
-// Tells the browser to update the spelling panel with the given word.
-IPC_MESSAGE_ROUTED1(SpellCheckHostMsg_UpdateSpellingPanelWithMisspelledWord,
-                    base::string16 /* the word to update the panel with */)
-
 // TODO(groby): This needs to originate from SpellcheckProvider.
 IPC_SYNC_MESSAGE_CONTROL2_1(SpellCheckHostMsg_CheckSpelling,
                             base::string16 /* word */,
                             int /* route_id */,
                             bool /* correct */)
 
 IPC_SYNC_MESSAGE_CONTROL1_1(SpellCheckHostMsg_FillSuggestionList,
                             base::string16 /* word */,
                             std::vector<base::string16> /* suggestions */)
 
 IPC_MESSAGE_CONTROL3(SpellCheckHostMsg_RequestTextCheck,
                      int /* route_id for response */,
                      int /* request identifier given by WebKit */,
                      base::string16 /* sentence */)
 
 IPC_MESSAGE_ROUTED2(SpellCheckHostMsg_ToggleSpellCheck,
                     bool /* enabled */,
                     bool /* checked */)
 #endif  // USE_BROWSER_SPELLCHECKER
+
+#if BUILDFLAG(HAS_SPELLCHECK_PANEL)
+// Tells the browser to display or not display the SpellingPanel
+IPC_MESSAGE_ROUTED1(SpellCheckHostMsg_ShowSpellingPanel,
+                    bool /* if true, then show it, otherwise hide it*/)
+
+// Tells the browser to update the spelling panel with the given word.
+IPC_MESSAGE_ROUTED1(SpellCheckHostMsg_UpdateSpellingPanelWithMisspelledWord,
+                    base::string16 /* the word to update the panel with */)
+#endif

[please use gerrit instead, 2017/04/14 14:19:58]

Since you're moving these around, would you mind grouping all
HAS_SPELLCHECK_PANEL messages together?

[Xiaocheng, 2017/04/14 17:27:35]

The messages are grouped as "from renderer to browser" and "from browser to
renderer".

So I guess the spellcheck panel messages should also be grouped like that.