Avoid element id collisions with the visual viewport

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/FrameHost.h"
 #include "core/frame/FrameView.h"
 #include "core/frame/LocalFrame.h"
 #include "core/frame/TopControls.h"
 #include "core/html/HTMLBodyElement.h"
 #include "core/html/HTMLElement.h"
 #include "core/input/EventHandler.h"
 #include "core/layout/LayoutObject.h"
 #include "core/layout/api/LayoutViewItem.h"
 #include "core/layout/compositing/PaintLayerCompositor.h"
 #include "core/page/Page.h"
 #include "platform/PlatformGestureEvent.h"
 #include "platform/geometry/DoublePoint.h"
 #include "platform/geometry/DoubleRect.h"
+#include "platform/graphics/CompositorElementId.h"
 #include "platform/testing/RuntimeEnabledFeaturesTestHelpers.h"
 #include "platform/testing/URLTestHelpers.h"
 #include "public/platform/Platform.h"
 #include "public/platform/WebCachePolicy.h"
 #include "public/platform/WebLayerTreeView.h"
 #include "public/platform/WebURLLoaderMockFactory.h"
 #include "public/web/WebCache.h"
 #include "public/web/WebContextMenuData.h"
 #include "public/web/WebDocument.h"
 #include "public/web/WebFrameClient.h"
@@ skipping 744 matching lines @@
   EXPECT_SIZE_EQ(FloatSize(50, 60), visualViewport.scrollOffset());
   EXPECT_EQ(2, visualViewport.scale());
 
   // Navigate again, this time the FrameView should be smaller.
   registerMockedHttpURLLoad("viewport-device-width.html");
   navigateTo(m_baseURL + "viewport-device-width.html");
 
   // Ensure the scroll layer matches the frame view's size.
   EXPECT_SIZE_EQ(FloatSize(320, 240), visualViewport.scrollLayer()->size());
 
+  EXPECT_EQ(static_cast<int>(CompositorSubElementId::Viewport),
+            visualViewport.scrollLayer()->elementId().secondaryId);
+
   // Ensure the location and scale were reset.
   EXPECT_SIZE_EQ(FloatSize(), visualViewport.scrollOffset());
   EXPECT_EQ(1, visualViewport.scale());
 }
 
 // The main FrameView's size should be set such that its the size of the visual
 // viewport at minimum scale. Test that the FrameView is appropriately sized in
 // the presence of a viewport <meta> tag.
 TEST_P(ParameterizedVisualViewportTest,
        TestFrameViewSizedToViewportMetaMinimumScale) {
@@ skipping 1269 matching lines @@
   webViewImpl()->resize(IntSize(600, 800));
 
   EXPECT_SIZE_EQ(ScrollOffset(),
                  frameView.layoutViewportScrollableArea()->scrollOffset());
   EXPECT_EQ(600, scroller->scrollTop());
 
   RuntimeEnabledFeatures::setSetRootScrollerEnabled(wasRootScrollerEnabled);
 }
 
 }  // namespace