Remove scroll layer ids from scrollbar layers

cc/trees/layer_tree_host_pixeltest_scrollbars.cc

 // 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 <stddef.h>
 
 #include "base/memory/ptr_util.h"
 #include "build/build_config.h"
 #include "cc/input/scrollbar.h"
 #include "cc/layers/painted_overlay_scrollbar_layer.h"
@@ skipping 70 matching lines @@
   SkColor color_ = SK_ColorGREEN;
   gfx::Rect rect_;
 };
 
 TEST_F(LayerTreeHostScrollbarsPixelTest, NoScale) {
   scoped_refptr<SolidColorLayer> background =
       CreateSolidColorLayer(gfx::Rect(200, 200), SK_ColorWHITE);
 
   auto scrollbar = base::MakeUnique<PaintedScrollbar>();
   scoped_refptr<PaintedScrollbarLayer> layer =
-      PaintedScrollbarLayer::Create(std::move(scrollbar), Layer::INVALID_ID);
+      PaintedScrollbarLayer::Create(std::move(scrollbar));
   layer->SetIsDrawable(true);
   layer->SetBounds(gfx::Size(200, 200));
   background->AddChild(layer);
 
   RunPixelTest(PIXEL_TEST_GL, background,
                base::FilePath(FILE_PATH_LITERAL("spiral.png")));
 }
 
 TEST_F(LayerTreeHostScrollbarsPixelTest, DeviceScaleFactor) {
   // With a device scale of 2, the scrollbar should still be rendered
   // pixel-perfect, not show scaling artifacts
   device_scale_factor_ = 2.f;
 
   scoped_refptr<SolidColorLayer> background =
       CreateSolidColorLayer(gfx::Rect(100, 100), SK_ColorWHITE);
 
   auto scrollbar = base::MakeUnique<PaintedScrollbar>();
   scoped_refptr<PaintedScrollbarLayer> layer =
-      PaintedScrollbarLayer::Create(std::move(scrollbar), Layer::INVALID_ID);
+      PaintedScrollbarLayer::Create(std::move(scrollbar));
   layer->SetIsDrawable(true);
   layer->SetBounds(gfx::Size(100, 100));
   background->AddChild(layer);
 
   RunPixelTest(PIXEL_TEST_GL, background,
                base::FilePath(FILE_PATH_LITERAL("spiral_double_scale.png")));
 }
 
 TEST_F(LayerTreeHostScrollbarsPixelTest, TransformScale) {
   scoped_refptr<SolidColorLayer> background =
       CreateSolidColorLayer(gfx::Rect(200, 200), SK_ColorWHITE);
 
   auto scrollbar = base::MakeUnique<PaintedScrollbar>();
   scoped_refptr<PaintedScrollbarLayer> layer =
-      PaintedScrollbarLayer::Create(std::move(scrollbar), Layer::INVALID_ID);
+      PaintedScrollbarLayer::Create(std::move(scrollbar));
   layer->SetIsDrawable(true);
   layer->SetBounds(gfx::Size(100, 100));
   background->AddChild(layer);
 
   // This has a scale of 2, it should still be rendered pixel-perfect, not show
   // scaling artifacts
   gfx::Transform scale_transform;
   scale_transform.Scale(2.0, 2.0);
   layer->SetTransform(scale_transform);
 
   RunPixelTest(PIXEL_TEST_GL, background,
                base::FilePath(FILE_PATH_LITERAL("spiral_double_scale.png")));
 }
 
 TEST_F(LayerTreeHostScrollbarsPixelTest, HugeTransformScale) {
   scoped_refptr<SolidColorLayer> background =
       CreateSolidColorLayer(gfx::Rect(400, 400), SK_ColorWHITE);
 
   auto scrollbar = base::MakeUnique<PaintedScrollbar>();
   scrollbar->set_paint_scale(1);
   scoped_refptr<PaintedScrollbarLayer> layer =
-      PaintedScrollbarLayer::Create(std::move(scrollbar), Layer::INVALID_ID);
+      PaintedScrollbarLayer::Create(std::move(scrollbar));
   layer->SetIsDrawable(true);
   layer->SetBounds(gfx::Size(10, 400));
   background->AddChild(layer);
 
   scoped_refptr<TestInProcessContextProvider> context(
       new TestInProcessContextProvider(nullptr));
   context->BindToCurrentThread();
   int max_texture_size = 0;
   context->ContextGL()->GetIntegerv(GL_MAX_TEXTURE_SIZE, &max_texture_size);
 
@@ skipping 74 matching lines @@
 };
 
 // Simulate increasing the thickness of a painted overlay scrollbar. Ensure that
 // the scrollbar border remains crisp.
 TEST_F(LayerTreeHostOverlayScrollbarsPixelTest, NinePatchScrollbarScaledUp) {
   scoped_refptr<SolidColorLayer> background =
       CreateSolidColorLayer(gfx::Rect(400, 400), SK_ColorWHITE);
 
   auto scrollbar = base::MakeUnique<PaintedOverlayScrollbar>();
   scoped_refptr<PaintedOverlayScrollbarLayer> layer =
-      PaintedOverlayScrollbarLayer::Create(std::move(scrollbar),
-                                           Layer::INVALID_ID);
+      PaintedOverlayScrollbarLayer::Create(std::move(scrollbar));
 
   scrollbar_layer_id_ = layer->id();
   thickness_scale_ = 5.f;
 
   layer->SetIsDrawable(true);
   layer->SetBounds(gfx::Size(10, 300));
   background->AddChild(layer);
 
   layer->SetPosition(gfx::PointF(185, 10));
 
   RunPixelTest(
       PIXEL_TEST_GL, background,
       base::FilePath(FILE_PATH_LITERAL("overlay_scrollbar_scaled_up.png")));
 }
 
 // Simulate decreasing the thickness of a painted overlay scrollbar. Ensure that
 // the scrollbar border remains crisp.
 TEST_F(LayerTreeHostOverlayScrollbarsPixelTest, NinePatchScrollbarScaledDown) {
   scoped_refptr<SolidColorLayer> background =
       CreateSolidColorLayer(gfx::Rect(400, 400), SK_ColorWHITE);
 
   auto scrollbar = base::MakeUnique<PaintedOverlayScrollbar>();
   scoped_refptr<PaintedOverlayScrollbarLayer> layer =
-      PaintedOverlayScrollbarLayer::Create(std::move(scrollbar),
-                                           Layer::INVALID_ID);
+      PaintedOverlayScrollbarLayer::Create(std::move(scrollbar));
 
   scrollbar_layer_id_ = layer->id();
   thickness_scale_ = 0.4f;
 
   layer->SetIsDrawable(true);
   layer->SetBounds(gfx::Size(10, 300));
   background->AddChild(layer);
 
   layer->SetPosition(gfx::PointF(185, 10));
 
   RunPixelTest(
       PIXEL_TEST_GL, background,
       base::FilePath(FILE_PATH_LITERAL("overlay_scrollbar_scaled_down.png")));
 }
 
 }  // namespace
 }  // namespace cc
 
 #endif  // OS_ANDROID