Implement link selection on alt+mouse drag.

third_party/WebKit/Source/web/tests/SelectionTestBase.h

+// Copyright (c) 2016 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 SelectionTestBase_h
+#define SelectionTestBase_h
+
+#include "web/WebLocalFrameImpl.h"
+#include "web/tests/FrameTestHelpers.h"
+
+#include <gtest/gtest.h>
+#include <string>
+
+namespace blink {
+class IntPoint;
+class WebViewImpl;
+class WebLocalFrameImpl;
+
+class SelectionTestBase : public ::testing::Test {

[kotenkov, 2016/03/09 17:27:59]

This class is not inside the LinkSelectionTest, because we use it for other
tests at Yandex, in particular for tests on table selection feature
(https://groups.google.com/a/chromium.org/forum/#!searchin/blink-dev/table$20s...).
If this is not acceptable, I can move it to the test file.

+protected:
+    void emulateMouseDrag(const IntPoint& downPoint, const IntPoint& upPoint, int modifiers,

[yosin_UTC9, 2016/03/10 01:40:49]

Could you avoid to use |bool| parameters?

+        bool sendDownEvent = true, bool sendUpEvent = true);
+
+    void emulateMouseClick(const IntPoint& clickPoint, WebMouseEvent::Button, int modifiers, int count = 1);
+    void emulateMouseDown(const IntPoint& clickPoint, WebMouseEvent::Button, int modifiers, int count = 1);
+
+    std::string getSelectionText();
+
+    FrameTestHelpers::WebViewHelper m_helper;
+    WebViewImpl* m_webView = nullptr;
+    RawPtrWillBePersistent<WebLocalFrameImpl> m_mainFrame = nullptr;
+};
+
+} // namespace blink
+
+#endif // SelectionTestBase_h