Fix scrollbar buttons on ChromeOS.

third_party/WebKit/Source/platform/scroll/ScrollbarThemeAuraTest.cpp

 // Copyright 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.
 
 #include "platform/scroll/ScrollbarThemeAura.h"
 
 #include "platform/scroll/ScrollbarTestSuite.h"
 
 namespace blink {
 
 using testing::Return;
 
+namespace {
+
+class ScrollbarThemeAuraButtonOverride final : public ScrollbarThemeAura {
+public:
+    ScrollbarThemeAuraButtonOverride()
+        : m_hasScrollbarButtons(true)
+    {
+    }
+
+    void setHasScrollbarButtons(bool value)
+    {
+        m_hasScrollbarButtons = value;
+    }
+
+    bool hasScrollbarButtons(ScrollbarOrientation unused) const override
+    {
+        return m_hasScrollbarButtons;
+    }
+
+private:
+    bool m_hasScrollbarButtons;
+};
+
+} // namespace
+
 class ScrollbarThemeAuraTest : public ScrollbarTestSuite {
 };
 
 TEST_F(ScrollbarThemeAuraTest, ButtonSizeHorizontal)
 {
     MockScrollableArea* mockScrollableArea = MockScrollableArea::create();
     ScrollbarThemeMock mockTheme;
     Scrollbar* scrollbar = Scrollbar::createForTesting(
         mockScrollableArea, HorizontalScrollbar, RegularScrollbar, &mockTheme);
-    ScrollbarThemeAura theme;
+    ScrollbarThemeAuraButtonOverride theme;
 
     IntRect scrollbarSizeNormalDimensions(11, 22, 444, 66);
     scrollbar->setFrameRect(scrollbarSizeNormalDimensions);
     IntSize size1 = theme.buttonSize(*scrollbar);
     EXPECT_EQ(66, size1.width());
     EXPECT_EQ(66, size1.height());
 
     IntRect scrollbarSizeSquashedDimensions(11, 22, 444, 666);
     scrollbar->setFrameRect(scrollbarSizeSquashedDimensions);
     IntSize size2 = theme.buttonSize(*scrollbar);
     EXPECT_EQ(222, size2.width());
     EXPECT_EQ(666, size2.height());
 
     ThreadHeap::collectAllGarbage();
 }
 
 TEST_F(ScrollbarThemeAuraTest, ButtonSizeVertical)
 {
     MockScrollableArea* mockScrollableArea = MockScrollableArea::create();
     ScrollbarThemeMock mockTheme;
     Scrollbar* scrollbar = Scrollbar::createForTesting(
         mockScrollableArea, VerticalScrollbar, RegularScrollbar, &mockTheme);
-    ScrollbarThemeAura theme;
+    ScrollbarThemeAuraButtonOverride theme;
 
     IntRect scrollbarSizeNormalDimensions(11, 22, 44, 666);
     scrollbar->setFrameRect(scrollbarSizeNormalDimensions);
     IntSize size1 = theme.buttonSize(*scrollbar);
     EXPECT_EQ(44, size1.width());
     EXPECT_EQ(44, size1.height());
 
     IntRect scrollbarSizeSquashedDimensions(11, 22, 444, 666);
     scrollbar->setFrameRect(scrollbarSizeSquashedDimensions);
     IntSize size2 = theme.buttonSize(*scrollbar);
     EXPECT_EQ(444, size2.width());
     EXPECT_EQ(333, size2.height());
 
     ThreadHeap::collectAllGarbage();
 }
 
+TEST_F(ScrollbarThemeAuraTest, NoButtonsReturnsSize0)
+{
+    MockScrollableArea* mockScrollableArea = MockScrollableArea::create();
+    ScrollbarThemeMock mockTheme;
+    Scrollbar* scrollbar = Scrollbar::createForTesting(
+        mockScrollableArea, VerticalScrollbar, RegularScrollbar, &mockTheme);
+    ScrollbarThemeAuraButtonOverride theme;
+    theme.setHasScrollbarButtons(false);
+
+    scrollbar->setFrameRect(IntRect(1, 2, 3, 4));
+    IntSize size = theme.buttonSize(*scrollbar);
+    EXPECT_EQ(0, size.width());
+    EXPECT_EQ(0, size.height());
+
+    ThreadHeap::collectAllGarbage();
+}
+
 } // namespace blink