Remove indirection: setup scrollbar scroll layers in the scrollbar constructor

third_party/WebKit/Source/platform/testing/TestingPlatformSupport.cpp

Index: third_party/WebKit/Source/platform/testing/TestingPlatformSupport.cpp
diff --git a/third_party/WebKit/Source/platform/testing/TestingPlatformSupport.cpp b/third_party/WebKit/Source/platform/testing/TestingPlatformSupport.cpp
index 59ba94724845531dba20609b291b92d62c4ebae2..e47eb909e775f34a27ecf9600517723532d14c5f 100644
--- a/third_party/WebKit/Source/platform/testing/TestingPlatformSupport.cpp
+++ b/third_party/WebKit/Source/platform/testing/TestingPlatformSupport.cpp
@@ -120,7 +120,8 @@ std::unique_ptr<WebScrollbarLayer>
 TestingCompositorSupport::createScrollbarLayer(
     std::unique_ptr<WebScrollbar>,
     WebScrollbarThemePainter,
-    std::unique_ptr<WebScrollbarThemeGeometry>) {
+    std::unique_ptr<WebScrollbarThemeGeometry>,
+    WebLayer* scrollLayer) {
   return nullptr;
 }
 
@@ -128,7 +129,8 @@ std::unique_ptr<WebScrollbarLayer>
 TestingCompositorSupport::createOverlayScrollbarLayer(
     std::unique_ptr<WebScrollbar>,
     WebScrollbarThemePainter,
-    std::unique_ptr<WebScrollbarThemeGeometry>) {
+    std::unique_ptr<WebScrollbarThemeGeometry>,
+    WebLayer* scrollLayer) {
   return nullptr;
 }
 
@@ -137,7 +139,8 @@ TestingCompositorSupport::createSolidColorScrollbarLayer(
     WebScrollbar::Orientation,
     int thumbThickness,
     int trackStart,
-    bool isLeftSideVerticalScrollbar) {
+    bool isLeftSideVerticalScrollbar,
+    WebLayer* scrollLayer) {
   return nullptr;
 }