Reland "Implement FullScreen using top layer."

third_party/WebKit/Source/core/css/resolver/StyleAdjuster.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 2004-2005 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2006, 2007 Nicholas Shanks (webkit@nickshanks.com)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Alexey Proskuryakov <ap@webkit.org>
  * Copyright (C) 2007, 2008 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (c) 2011, Code Aurora Forum. All rights reserved.
  * Copyright (C) Research In Motion Limited 2011. All rights reserved.
@@ skipping 15 matching lines @@
  * Boston, MA 02110-1301, USA.
  */
 
 #include "core/css/resolver/StyleAdjuster.h"
 
 #include "core/HTMLNames.h"
 #include "core/SVGNames.h"
 #include "core/dom/ContainerNode.h"
 #include "core/dom/Document.h"
 #include "core/dom/Element.h"
+#include "core/dom/Fullscreen.h"
+#include "core/frame/FrameHost.h"
 #include "core/frame/FrameView.h"
 #include "core/frame/Settings.h"
 #include "core/frame/UseCounter.h"
+#include "core/frame/VisualViewport.h"
 #include "core/html/HTMLIFrameElement.h"
 #include "core/html/HTMLInputElement.h"
 #include "core/html/HTMLPlugInElement.h"
 #include "core/html/HTMLTableCellElement.h"
 #include "core/html/HTMLTextAreaElement.h"
 #include "core/layout/LayoutTheme.h"
+#include "core/page/Page.h"
 #include "core/style/ComputedStyle.h"
 #include "core/style/ComputedStyleConstants.h"
 #include "core/svg/SVGSVGElement.h"
 #include "platform/Length.h"
 #include "platform/transforms/TransformOperations.h"
 #include "wtf/Assertions.h"
 
 namespace blink {
 
 using namespace HTMLNames;
@@ skipping 111 matching lines @@
         // We don't adjust the first letter style earlier because we may change the display setting in
         // adjustStyeForTagName() above.
         adjustStyleForFirstLetter(style);
 
         adjustStyleForDisplay(style, parentStyle, element ? &element->document() : 0);
 
         // Paint containment forces a block formatting context, so we must coerce from inline.
         // https://drafts.csswg.org/css-containment/#containment-paint
         if (style.containsPaint() && style.display() == INLINE)
             style.setDisplay(BLOCK);
+
+        if (element && Fullscreen::isActiveFullScreenElement(*element)) {
+            // We need to size the fullscreen element to the inner viewport and not to the
+            // outer viewport (what percentage would do). Unfortunately CSS can't handle
+            // that as we don't expose the inner viewport information.
+            //
+            // TODO(dsinclair): We should find a way to get this standardized. crbug.com/534924

[foolip, 2016/06/29 20:11:00]

dsinclair@, can you fill me in about the purpose of this? Is there any
connection to https://bugs.chromium.org/p/chromium/issues/detail?id=543946 and
https://github.com/whatwg/fullscreen/issues/19 where the question is whether
top-layer should end up on top of scrollbars?

[dsinclair, 2016/06/29 20:14:47]

I'm not sure if this is what causes the scrollbar bug or not, I'm not too
familiar with the viewport stuff. The TODO was that we, preferrably, want a way
for CSS to expose the inner viewport instead of forcing it here.

[foolip, 2016/06/30 14:33:24]

I tried reverting this and running test to understand what the difference is,
but no tests failed :)

Is the visual viewport the pinch zoom viewport, or something else? There are
some tricks in FullscreenController to save and restore scale and
scroll/viewport offsets, is this related?

[dsinclair, 2016/07/06 13:32:31]

I was never really clear on viewport. There is an inner and outer viewport used
for pinch-zoom. I'm not sure how those relate to the visual viewport, if at all.
You could try asking bokan@ as he did a lot of viewport work.

[foolip, 2016/07/06 14:14:51]

Thanks, I'll do that if I can't figure this out.

+            IntSize viewportSize = element->document().page()->frameHost().visualViewport().size();
+            style.setWidth(Length(viewportSize.width(), Fixed));
+            style.setHeight(Length(viewportSize.height(), Fixed));
+        }
     } else {
         adjustStyleForFirstLetter(style);
     }
 
     if (element && element->hasCompositorProxy())
         style.setHasCompositorProxy(true);
 
     // Make sure our z-index value is only applied if the object is positioned.
     if (style.position() == StaticPosition && !parentStyleForcesZIndexToCreateStackingContext(parentStyle))
         style.setHasAutoZIndex();
@@ skipping 266 matching lines @@
         // We want to count vertical percentage paddings/margins on flex items because our current
         // behavior is different from the spec and we want to gather compatibility data.
         if (style.paddingBefore().hasPercent() || style.paddingAfter().hasPercent())
             UseCounter::count(document, UseCounter::FlexboxPercentagePaddingVertical);
         if (style.marginBefore().hasPercent() || style.marginAfter().hasPercent())
             UseCounter::count(document, UseCounter::FlexboxPercentageMarginVertical);
     }
 }
 
 } // namespace blink