Build chromedriver2 library on the chromedriver waterfall.

It is needed by the python integration tests
NOTRY=true

Review URL: https://chromiumcodereview.appspot.com/14657024

git-svn-id: http://src.chromium.org/svn/trunk/src/build@200058 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

all.gyp

@@ -429,6 +429,7 @@
           'target_name': 'chromium_builder_chromedriver',
           'type': 'none',
           'dependencies': [
+            '../chrome/chrome.gyp:chromedriver2',
             '../chrome/chrome.gyp:chromedriver2_server',
             '../chrome/chrome.gyp:chromedriver2_tests',
             '../chrome/chrome.gyp:chromedriver2_unittests',