Add nacl_helper to interactive_ui_tests' isolate to make...

Add nacl_helper to interactive_ui_tests' isolate to make LoggedInSpokenFeedbackTest.AddBookmark pass.

BUG=414808
TBR=dmazzoni@chromium.org

Review URL: https://codereview.chromium.org/607543002

Cr-Commit-Position: refs/heads/master@{#296708}

chrome/interactive_ui_tests.isolate

@@ -104,6 +104,7 @@
         'isolate_dependency_tracked': [
           '<(PRODUCT_DIR)/keyboard_resources.pak',
           '<(PRODUCT_DIR)/libexif.so',
+          '<(PRODUCT_DIR)/nacl_helper',
           '<(PRODUCT_DIR)/nacl_irt_x86_64.nexe',
         ],
         'isolate_dependency_untracked': [