Fix event targeting for overlay scrollbar thumbs (in native UI).

ui/views/controls/scroll_view_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 "ui/views/controls/scroll_view.h"
 
 #include "base/macros.h"
 #include "base/run_loop.h"
 #include "base/test/test_timeouts.h"
 #include "base/threading/thread_task_runner_handle.h"
@@ skipping 514 matching lines @@
   CustomView* header = new CustomView;
   scroll_view_.SetHeader(header);
   header->SetPreferredSize(gfx::Size(500, 20));
 
   scroll_view_.SetBoundsRect(gfx::Rect(0, 0, 100, 100));
   EXPECT_EQ("0,0", test_api.IntegralViewOffset().ToString());
   EXPECT_EQ("0,0", header->bounds().origin().ToString());
 
   // Scroll the horizontal scrollbar.
   ASSERT_TRUE(scroll_view_.horizontal_scroll_bar());
-  scroll_view_.ScrollToPosition(
-      const_cast<ScrollBar*>(scroll_view_.horizontal_scroll_bar()), 1);
+  scroll_view_.ScrollToPosition(test_api.GetBaseScrollBar(HORIZONTAL), 1);
   EXPECT_EQ("-1,0", test_api.IntegralViewOffset().ToString());
   EXPECT_EQ("-1,0", header->bounds().origin().ToString());
 
   // Scrolling the vertical scrollbar shouldn't effect the header.
   ASSERT_TRUE(scroll_view_.vertical_scroll_bar());
-  scroll_view_.ScrollToPosition(
-      const_cast<ScrollBar*>(scroll_view_.vertical_scroll_bar()), 1);
+  scroll_view_.ScrollToPosition(test_api.GetBaseScrollBar(VERTICAL), 1);
   EXPECT_EQ("-1,-1", test_api.IntegralViewOffset().ToString());
   EXPECT_EQ("-1,0", header->bounds().origin().ToString());
 }
 
 // Verifies ScrollRectToVisible() on the child works.
 TEST_F(ScrollViewTest, ScrollRectToVisible) {
   ScrollViewTestApi test_api(&scroll_view_);
   CustomView* contents = new CustomView;
   scroll_view_.SetContents(contents);
   contents->SetPreferredSize(gfx::Size(500, 1000));
@@ skipping 322 matching lines @@
   CustomView* contents = new CustomView;
   contents->SetPreferredSize(gfx::Size(300, 300));
   scroll_view_.SetContents(contents);
   scroll_view_.ClipHeightTo(0, 150);
   scroll_view_.SizeToPreferredSize();
   // ScrollView preferred width matches that of |contents|, with the height
   // capped at the value we clipped to.
   EXPECT_EQ(gfx::Size(300, 150), scroll_view_.size());
 
   // Scroll down.
-  scroll_view_.ScrollToPosition(
-      const_cast<ScrollBar*>(scroll_view_.vertical_scroll_bar()), 25);
+  scroll_view_.ScrollToPosition(test_api.GetBaseScrollBar(VERTICAL), 25);
   EXPECT_EQ(25, test_api.CurrentOffset().y());
   // Call Layout; no change to scroll position.
   scroll_view_.Layout();
   EXPECT_EQ(25, test_api.CurrentOffset().y());
   // Change contents of |contents|, call Layout; still no change to scroll
   // position.
   contents->SetPreferredSize(gfx::Size(300, 500));
   contents->InvalidateLayout();
   scroll_view_.Layout();
   EXPECT_EQ(25, test_api.CurrentOffset().y());
@@ skipping 123 matching lines @@
   // Scroll via ScrollView API. Should be reflected on the impl side.
   offset.set_y(kDefaultHeight * 4);
   scroll_view->contents()->ScrollRectToVisible(offset);
   EXPECT_EQ(gfx::ScrollOffset(0, offset.y()), test_api.CurrentOffset());
 
   EXPECT_TRUE(compositor->GetScrollOffsetForLayer(layer_id, &impl_offset));
   EXPECT_EQ(gfx::ScrollOffset(0, offset.y()), impl_offset);
 }
 
 }  // namespace views