Hook third_party/chromeos_text_input to all.gyp for Chromium OS.

chromiumos_text_input contains IME candidate window code which is part
of text input suppport for Chromium OS.
See the design doc for details:
http://www.chromium.org/chromium-os/chromiumos-design-docs/text-input

BUG=none
TEST=confirmed gclient --runhooks work with and without GYP_DEFINES="chromeos=1". Also confirmed that 'candidate_window' target is only valid and built when GYP_DEFINES="chromeos=1" is set.

Review URL: http://codereview.chromium.org/551043

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@36484 0039d316-1c4b-4281-b951-d872f2087c98

build/all.gyp

@@ -116,6 +116,11 @@
             '../views/views.gyp:*',
           ],
         }],
+        ['chromeos==1', {
+          'dependencies': [
+            '../third_party/chromeos_text_input/text_input.gyp:*',
+          ],
+        }],
       ],
     },
   ],