Disable "Ok Google" hotwording in open source builds by default.

chrome/browser/BUILD.gn

Index: chrome/browser/BUILD.gn
diff --git a/chrome/browser/BUILD.gn b/chrome/browser/BUILD.gn
index 63e9053cb1af5215aab9cf7d2fee2014a7d435e2..5f372d9725a1e3ad3935739776475c1238e2df37 100644
--- a/chrome/browser/BUILD.gn
+++ b/chrome/browser/BUILD.gn
@@ -20,8 +20,10 @@ if (is_desktop_linux) {
 }
 
 declare_args() {
-  # 'Ok Google' hotwording is enabled.
-  enable_hotwording = true
+  # 'Ok Google' hotwording is disabled by default in open source builds. Set to
+  # true to enable. (This will download a closed-source NaCl module at startup.)
+  # Official builds have this enabled by default.
+  enable_hotwording = is_official_build

[Anand Mistry (off Chromium), 2015/06/24 01:10:33]

s/is_official_build/is_chrome_branded/

[Matt Giuca, 2015/06/24 01:41:54]

Done.

 }
 
 about_credits_file = "$target_gen_dir/about_credits.html"