Add build flag to disable hotwording.

build/common.gypi

Index: build/common.gypi
diff --git a/build/common.gypi b/build/common.gypi
index 1866de0f3872da715a62fe133f4ae487c1019beb..53b9f8a9f6deec917d52483134657467bb56ee40 100644
--- a/build/common.gypi
+++ b/build/common.gypi
@@ -417,6 +417,9 @@
       # Web speech is enabled by default. Set to 0 to disable.
       'enable_web_speech%': 1,
 
+      # 'Ok Google' hotwording is disabled by default. Set to 1 to enable.
+      'enable_hotwording%': 0,
+
       # Notifications are compiled in by default. Set to 0 to disable.
       'notifications%' : 1,
 
@@ -1152,6 +1155,7 @@
     'configuration_policy%': '<(configuration_policy)',
     'safe_browsing%': '<(safe_browsing)',
     'enable_web_speech%': '<(enable_web_speech)',
+    'enable_hotwording%': '<(enable_hotwording)',
     'notifications%': '<(notifications)',
     'clang_use_chrome_plugins%': '<(clang_use_chrome_plugins)',
     'mac_want_real_dsym%': '<(mac_want_real_dsym)',
@@ -2419,8 +2423,9 @@
         'use_lto%': 1,
       }],
 
-      ['branding=="Chrome" and buildtype=="Official"', {
+      ['branding=="Chrome"', {
         'enable_hangout_services_extension%': 1,
+        'enable_hotwording%' : 1,

[scottmg, 2015/06/03 05:48:08]

nit; no space before :

[Anand Mistry (off Chromium), 2015/06/03 22:54:08]

Done.

       }, {
         'enable_hangout_services_extension%': 0,
       }],