Route Scroll events through a cc::InputHandler

ui/views/controls/scrollbar/scrollbar_unittest.cc

 // 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.
 
 #include "build/build_config.h"
 #include "ui/views/controls/scrollbar/scroll_bar.h"
 #include "ui/views/controls/scrollbar/scroll_bar_views.h"
 #include "ui/views/test/views_test_base.h"
 #include "ui/views/widget/widget.h"
 
@@ skipping 15 matching lines @@
                          bool is_positive) override {
     last_source = source;
     last_is_page = is_page;
     last_is_positive = is_positive;
 
     if (is_page)
       return 20;
     return 10;
   }
 
+  void OnScrollEventFromScrollBar(ui::ScrollEvent* event) override {}
+
   // We save the last values in order to assert the correctness of the scroll
   // operation.
   views::ScrollBar* last_source;
   bool last_is_positive;
   bool last_is_page;
   int last_position;
 };
 
 }  // namespace
 
@@ skipping 138 matching lines @@
             scrollbar_->GetThumbSizeForTest());
   // Emulate a click on the full size scroll bar.
   scrollbar_->ScrollToThumbPosition(0, false);
   EXPECT_EQ(0, scrollbar_->GetPosition());
   // Emulate a key down.
   scrollbar_->ScrollByAmount(BaseScrollBar::SCROLL_NEXT_LINE);
   EXPECT_EQ(0, scrollbar_->GetPosition());
 }
 
 }  // namespace views