Add unittest to test CWVWebView.

ios/web_view/test/web_view_interaction_test_util.h

Index: ios/web_view/test/web_view_interaction_test_util.h
diff --git a/ios/web_view/test/web_view_interaction_test_util.h b/ios/web_view/test/web_view_interaction_test_util.h
new file mode 100644
index 0000000000000000000000000000000000000000..89f2cf10e8567d91241d738db016d6492af2f14f
--- /dev/null
+++ b/ios/web_view/test/web_view_interaction_test_util.h
@@ -0,0 +1,19 @@
+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef IOS_WEB_VIEW_TEST_WEB_VIEW_INTERACTION_TEST_UTIL_H_
+#define IOS_WEB_VIEW_TEST_WEB_VIEW_INTERACTION_TEST_UTIL_H_
+
+@class CWVWebView;
+@class NSString;
+
+namespace ios_web_view {
+namespace test {
+
+bool TapChromeWebViewElementWithId(CWVWebView* web_view, NSString* element_id);
+
+}  // namespace test
+}  // namespace ios_web_view
+
+#endif  // IOS_WEB_VIEW_TEST_WEB_VIEW_INTERACTION_TEST_UTIL_H_