Patch 2: Added a preprocessor flag for platform spellcheck.

build/common.gypi

Index: build/common.gypi
diff --git a/build/common.gypi b/build/common.gypi
index c0e184133ef31bcc0863ce865dd08278e08bfd03..a05759da68cd9583ead2ff4ff90a2e6b89810c6f 100644
--- a/build/common.gypi
+++ b/build/common.gypi
@@ -567,6 +567,9 @@
       # Enable spell checker.
       'enable_spellcheck%': 1,
 
+      # Signify that the platform has a native spellchecker.

[please use gerrit instead, 2015/07/02 04:27:05]

This comment can be confusing, because "native" means "hunspell" here:

https://code.google.com/p/chromium/codesearch#chromium/src/chrome/renderer/sp...

I suggest this comment instead:

# Use the operating system spellchecker, e.g. on NSSpellChecker on Mac or
SpellCheckerService on Android.

(Is that the correct API name for Android?)

[dylanking, 2015/07/07 02:31:22]

Fixed in https://codereview.chromium.org/1227553002 so that I could apply the
changes to all the new or already modified code that's not in this CL.  

[dylanking, 2015/07/07 19:02:15]

Now fixed here, too.

+      'use_platform_spellchecker%': 0,
+
       # Webrtc compilation is enabled by default. Set to 0 to disable.
       'enable_webrtc%': 1,
 
@@ -818,6 +821,11 @@
           'video_hole%': 1,
         }],
 
+        # Android and OSX have native spellcheckers that we can utilize.

[please use gerrit instead, 2015/07/02 04:27:05]

s/native/operating system/

Or anything other term you pick instead of the word "native".

[dylanking, 2015/07/07 02:31:22]

Fixed in https://codereview.chromium.org/1227553002 so that I could apply the
changes to all the new or already modified code that's not in this CL.

[dylanking, 2015/07/07 19:02:15]

Now fixed here, too.

+        ['OS=="android" or OS=="mac"', {
+          'use_platform_spellchecker%': 1,
+        }],
+
         # Android OS includes support for proprietary codecs regardless of
         # building Chromium or Google Chrome. We also ship Google Chrome and
         # Chromecast with proprietary codecs.
@@ -1193,6 +1201,7 @@
     'enable_basic_printing%': '<(enable_basic_printing)',
     'enable_print_preview%': '<(enable_print_preview)',
     'enable_spellcheck%': '<(enable_spellcheck)',
+    'use_platform_spellchecker%': '<(use_platform_spellchecker)',
     'enable_google_now%': '<(enable_google_now)',
     'cld_version%': '<(cld_version)',
     'cld2_table_size%': '<(cld2_table_size)',
@@ -2984,6 +2993,9 @@
       ['enable_spellcheck==1', {
         'defines': ['ENABLE_SPELLCHECK=1'],
       }],
+      ['use_platform_spellchecker', {
+        'defines': ['USE_PLATFORM_SPELLCHECKER=1'],
+      }],
       ['enable_captive_portal_detection==1', {
         'defines': ['ENABLE_CAPTIVE_PORTAL_DETECTION=1'],
       }],