Fix PPB_MouseLock.LockMouse crash and add tests.

ppapi/tests/test_mouse_lock.h

Index: ppapi/tests/test_mouse_lock.h
diff --git a/ppapi/tests/test_mouse_lock.h b/ppapi/tests/test_mouse_lock.h
new file mode 100644
index 0000000000000000000000000000000000000000..0b101dde9fe1ce57aca786c594e98159505b8d99
--- /dev/null
+++ b/ppapi/tests/test_mouse_lock.h
@@ -0,0 +1,39 @@
+// Copyright (c) 2012 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 PAPPI_TESTS_TEST_MOUSE_LOCK_H_
+#define PPAPI_TESTS_TEST_MOUSE_LOCK_H_
+
+#include <string>
+
+#include "ppapi/cpp/mouse_lock.h"
+#include "ppapi/cpp/rect.h"
+#include "ppapi/tests/test_case.h"
+#include "ppapi/tests/test_utils.h"
+
+class TestMouseLock: public TestCase, public pp::MouseLock {
+ public:
+  explicit TestMouseLock(TestingInstance* instance);
+  virtual ~TestMouseLock();
+
+  // TestCase implementation.
+  virtual bool Init();
+  virtual void RunTests(const std::string& filter);
+  virtual void DidChangeView(const pp::View& view);
+
+  // pp::MouseLock implementation.
+  virtual void MouseLockLost();
+
+ private:
+  std::string TestSucceedWhenAllowed();
+  std::string TestFailWhenBlocked();
+
+  void SimulateUserGesture();
+
+  pp::Rect position_;
+
+  NestedEvent nested_event_;
+};
+
+#endif  // PPAPI_TESTS_TEST_MOUSE_LOCK_H_