Makes the language detection happen with every page load 
as we do with the page indexing. (The language detection was
previously done on demand when the extension related API was querying it.)
Once detected the language is stored on the navigation entry.
It'll be used for the upcoming translation feature.

Also I moved the existing language detection from the UI to
the file thread.

The change required few changes for the
chrome.tabs.detectLanguage extension API to still work.

BUG=None
TEST=Run the browser tests and unit-tests.

Review URL: http://codereview.chromium.org/492024

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@34728 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/chrome/chrome_browser.gypi b/chrome/chrome_browser.gypi
index 27910311..70110e6 100755
--- a/chrome/chrome_browser.gypi
+++ b/chrome/chrome_browser.gypi
@@ -291,6 +291,8 @@
         'browser/chromeos/usb_mount_observer.h',
         'browser/chromeos/version_loader.cc',
         'browser/chromeos/version_loader.h',
+        'browser/cld_helper.cc',
+        'browser/cld_helper.h',
         'browser/cocoa/about_ipc_bridge.h',
         'browser/cocoa/about_ipc_bridge.mm',
         'browser/cocoa/about_ipc_controller.h',