[RLS] Don't create PaintLayerCompositor layers.

third_party/WebKit/Source/web/tests/VisualViewportTest.cpp

 // Copyright 2014 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 "core/frame/VisualViewport.h"
 
 #include "core/dom/Document.h"
 #include "core/frame/BrowserControls.h"
 #include "core/frame/FrameHost.h"
 #include "core/frame/FrameView.h"
@@ skipping 416 matching lines @@
 
   EXPECT_SIZE_EQ(ScrollOffset(0, 0), frame()->view()->getScrollOffset());
   EXPECT_FLOAT_SIZE_EQ(FloatSize(150, 0), visualViewport.getScrollOffset());
 }
 
 // Test that the container layer gets sized properly if the WebView is resized
 // prior to the VisualViewport being attached to the layer tree.
 TEST_P(VisualViewportTest, TestWebViewResizedBeforeAttachment) {
   initializeWithDesktopSettings();
   FrameView& frameView = *webViewImpl()->mainFrameImpl()->frameView();
-  GraphicsLayer* rootGraphicsLayer =
-      frameView.layoutViewItem().compositor()->rootGraphicsLayer();
 
   // Make sure that a resize that comes in while there's no root layer is
   // honoured when we attach to the layer tree.
   WebFrameWidgetBase* mainFrameWidget =
       webViewImpl()->mainFrameImpl()->frameWidget();
   mainFrameWidget->setRootGraphicsLayer(nullptr);
   webViewImpl()->resize(IntSize(320, 240));
-  mainFrameWidget->setRootGraphicsLayer(rootGraphicsLayer);
 
   navigateTo("about:blank");
   webViewImpl()->updateAllLifecyclePhases();
+  mainFrameWidget->setRootGraphicsLayer(
+      frameView.layoutViewItem().compositor()->rootGraphicsLayer());
 
   VisualViewport& visualViewport =
       frame()->page()->frameHost().visualViewport();
   EXPECT_FLOAT_SIZE_EQ(FloatSize(320, 240),
                        visualViewport.containerLayer()->size());
 }
 
 // Make sure that the visibleRect method acurately reflects the scale and scroll
 // location of the viewport.
 TEST_P(VisualViewportTest, TestVisibleRect) {
@@ skipping 2012 matching lines @@
                                    "  body {"
                                    "    margin: 0px;"
                                    "  }"
                                    "  div { height:110vh; width: 110vw; }"
                                    "</style>"
                                    "<div></div>",
                                    baseURL);
 }
 
 }  // namespace