CompositingReasonFinder should use a virtual function instead of a nest of branches

This CL begins to move CompositingReasonFinder to using a virtual function on
RenderObject instead of a nest of "if video, if canvas" branches. This CL only creates
two overrides, one for video and one for canvas. A future CL will create
overrides for plugins and iframes, but there's some cleanup work we need to do first.

Review URL: https://codereview.chromium.org/197533013

git-svn-id: svn://svn.chromium.org/blink/trunk@169685 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/Source/core/page/ChromeClient.h

@@ -29,6 +29,7 @@
 #include "core/frame/ConsoleTypes.h"
 #include "core/page/FocusType.h"
 #include "core/rendering/RenderEmbeddedObject.h"
+#include "core/rendering/compositing/CompositingTriggers.h"
 #include "core/rendering/style/RenderStyleConstants.h"
 #include "platform/Cursor.h"
 #include "platform/HostWindow.h"
@@ -192,20 +193,8 @@ public:
     // Pass 0 as the GraphicsLayer to detatch the root layer.
     virtual void attachRootGraphicsLayer(GraphicsLayer*) = 0;
 
-    enum CompositingTrigger {
-        ThreeDTransformTrigger = 1 << 0,
-        VideoTrigger = 1 << 1,
-        PluginTrigger = 1 << 2,
-        CanvasTrigger = 1 << 3,
-        AnimationTrigger = 1 << 4,
-        FilterTrigger = 1 << 5,
-        ScrollableInnerFrameTrigger = 1 << 6,
-        AllTriggers = 0xFFFFFFFF
-    };
-    typedef unsigned CompositingTriggerFlags;
-
     // Returns a bitfield indicating conditions that can trigger the compositor.
-    virtual CompositingTriggerFlags allowedCompositingTriggers() const { return static_cast<CompositingTriggerFlags>(AllTriggers); }
+    virtual CompositingTriggerFlags allowedCompositingTriggers() const { return static_cast<CompositingTriggerFlags>(AllCompositingTriggers); }
 
     virtual void enterFullScreenForElement(Element*) { }
     virtual void exitFullScreenForElement(Element*) { }

third_party/WebKit/Source/core/rendering/RenderHTMLCanvas.cpp

@@ -111,4 +111,16 @@ void RenderHTMLCanvas::canvasSizeChanged()
         setNeedsLayout();
 }
 
+CompositingReasons RenderHTMLCanvas::additionalCompositingReasons(CompositingTriggerFlags triggers) const
+{
+    if (!(triggers & CanvasTrigger))
+        return CompositingReasonNone;
+
+    HTMLCanvasElement* canvas = toHTMLCanvasElement(node());
+    if (canvas->renderingContext() && canvas->renderingContext()->isAccelerated())
+        return CompositingReasonCanvas;
+
+    return CompositingReasonNone;
+}
+
 } // namespace WebCore

third_party/WebKit/Source/core/rendering/RenderHTMLCanvas.h

@@ -45,6 +45,8 @@ private:
     virtual const char* renderName() const OVERRIDE { return "RenderHTMLCanvas"; }
     virtual void paintReplaced(PaintInfo&, const LayoutPoint&) OVERRIDE;
     virtual void intrinsicSizeChanged() OVERRIDE { canvasSizeChanged(); }
+
+    virtual CompositingReasons additionalCompositingReasons(CompositingTriggerFlags) const OVERRIDE;
 };
 
 DEFINE_RENDER_OBJECT_TYPE_CASTS(RenderHTMLCanvas, isCanvas());

third_party/WebKit/Source/core/rendering/RenderObject.cpp

@@ -2784,6 +2784,11 @@ CompositingState RenderObject::compositingState() const
     return hasLayer() ? toRenderLayerModelObject(this)->layer()->compositingState() : NotComposited;
 }
 
+CompositingReasons RenderObject::additionalCompositingReasons(CompositingTriggerFlags) const
+{
+    return CompositingReasonNone;
+}
+
 bool RenderObject::acceleratedCompositingForOverflowScrollEnabled() const
 {
     const Settings* settings = document().settings();

third_party/WebKit/Source/core/rendering/RenderObject.h

@@ -35,10 +35,12 @@
 #include "core/rendering/RenderObjectChildList.h"
 #include "core/rendering/ScrollAlignment.h"
 #include "core/rendering/SubtreeLayoutScope.h"
+#include "core/rendering/compositing/CompositingTriggers.h"
 #include "core/rendering/style/RenderStyle.h"
 #include "core/rendering/style/StyleInheritedData.h"
 #include "platform/geometry/FloatQuad.h"
 #include "platform/geometry/LayoutRect.h"
+#include "platform/graphics/CompositingReasons.h"
 #include "platform/transforms/TransformationMatrix.h"
 
 namespace WebCore {
@@ -676,6 +678,8 @@ public:
     void collectAnnotatedRegions(Vector<AnnotatedRegionValue>&);
 
     CompositingState compositingState() const;
+    virtual CompositingReasons additionalCompositingReasons(CompositingTriggerFlags) const;
+
     bool acceleratedCompositingForOverflowScrollEnabled() const;
     // FIXME: This is a temporary flag and should be removed once accelerated
     // overflow scroll is ready (crbug.com/254111).

third_party/WebKit/Source/core/rendering/RenderVideo.cpp

@@ -276,4 +276,18 @@ LayoutUnit RenderVideo::offsetHeight() const
     return RenderMedia::offsetHeight();
 }
 
+CompositingReasons RenderVideo::additionalCompositingReasons(CompositingTriggerFlags triggers) const
+{
+    if (RuntimeEnabledFeatures::overlayFullscreenVideoEnabled()) {
+        HTMLMediaElement* media = toHTMLMediaElement(node());
+        if (media->isFullscreen())
+            return CompositingReasonVideo;
+    }
+
+    if ((triggers & VideoTrigger) && shouldDisplayVideo() && supportsAcceleratedRendering())
+        return CompositingReasonVideo;
+
+    return CompositingReasonNone;
+}
+
 } // namespace WebCore

third_party/WebKit/Source/core/rendering/RenderVideo.h

@@ -74,6 +74,8 @@ private:
     virtual LayoutUnit offsetWidth() const OVERRIDE;
     virtual LayoutUnit offsetHeight() const OVERRIDE;
 
+    virtual CompositingReasons additionalCompositingReasons(CompositingTriggerFlags) const OVERRIDE;
+
     void updatePlayer();
 
     bool acceleratedRenderingInUse();

third_party/WebKit/Source/core/rendering/compositing/CompositingReasonFinder.cpp

@@ -34,7 +34,7 @@ namespace WebCore {
 
 CompositingReasonFinder::CompositingReasonFinder(RenderView& renderView)
     : m_renderView(renderView)
-    , m_compositingTriggers(static_cast<ChromeClient::CompositingTriggerFlags>(ChromeClient::AllTriggers))
+    , m_compositingTriggers(static_cast<CompositingTriggerFlags>(AllCompositingTriggers))
 {
 }
 
@@ -45,12 +45,12 @@ void CompositingReasonFinder::updateTriggers()
 
 bool CompositingReasonFinder::has3DTransformTrigger() const
 {
-    return m_compositingTriggers & ChromeClient::ThreeDTransformTrigger;
+    return m_compositingTriggers & ThreeDTransformTrigger;
 }
 
 bool CompositingReasonFinder::hasAnimationTrigger() const
 {
-    return m_compositingTriggers & ChromeClient::AnimationTrigger;
+    return m_compositingTriggers & AnimationTrigger;
 }
 
 bool CompositingReasonFinder::isMainFrame() const
@@ -68,11 +68,8 @@ CompositingReasons CompositingReasonFinder::directReasons(const RenderLayer* lay
         directReasons |= CompositingReason3DTransform;
 
     // Only zero or one of the following conditions will be true for a given RenderLayer.
-    if (requiresCompositingForVideo(renderer))
-        directReasons |= CompositingReasonVideo;
-    else if (requiresCompositingForCanvas(renderer))
-        directReasons |= CompositingReasonCanvas;
-    else if (requiresCompositingForPlugin(renderer, needToRecomputeCompositingRequirements))
+    // FIXME: These should be handled by overrides of RenderObject::additionalCompositingReasons.
+    if (requiresCompositingForPlugin(renderer, needToRecomputeCompositingRequirements))
         directReasons |= CompositingReasonPlugin;
     else if (requiresCompositingForFrame(renderer))
         directReasons |= CompositingReasonIFrame;
@@ -104,6 +101,8 @@ CompositingReasons CompositingReasonFinder::directReasons(const RenderLayer* lay
     if (requiresCompositingForWillChange(renderer))
         directReasons |= CompositingReasonWillChange;
 
+    directReasons |= renderer->additionalCompositingReasons(m_compositingTriggers);
+
     return directReasons;
 }
 
@@ -114,7 +113,7 @@ bool CompositingReasonFinder::requiresCompositingForScrollableFrame() const
     if (isMainFrame())
         return false;
 
-    if (!(m_compositingTriggers & ChromeClient::ScrollableInnerFrameTrigger))
+    if (!(m_compositingTriggers & ScrollableInnerFrameTrigger))
         return false;
 
     FrameView* frameView = m_renderView.frameView();
@@ -123,7 +122,7 @@ bool CompositingReasonFinder::requiresCompositingForScrollableFrame() const
 
 bool CompositingReasonFinder::requiresCompositingForTransform(RenderObject* renderer) const
 {
-    if (!(m_compositingTriggers & ChromeClient::ThreeDTransformTrigger))
+    if (!(m_compositingTriggers & ThreeDTransformTrigger))
         return false;
 
     RenderStyle* style = renderer->style();
@@ -132,39 +131,9 @@ bool CompositingReasonFinder::requiresCompositingForTransform(RenderObject* rend
     return renderer->hasTransform() && style->transform().has3DOperation();
 }
 
-bool CompositingReasonFinder::requiresCompositingForVideo(RenderObject* renderer) const
-{
-    if (RuntimeEnabledFeatures::overlayFullscreenVideoEnabled() && renderer->isVideo()) {
-        HTMLMediaElement* media = toHTMLMediaElement(renderer->node());
-        if (media->isFullscreen())
-            return true;
-    }
-
-    if (!(m_compositingTriggers & ChromeClient::VideoTrigger))
-        return false;
-
-    if (renderer->isVideo()) {
-        RenderVideo* video = toRenderVideo(renderer);
-        return video->shouldDisplayVideo() && video->supportsAcceleratedRendering();
-    }
-    return false;
-}
-
-bool CompositingReasonFinder::requiresCompositingForCanvas(RenderObject* renderer) const
-{
-    if (!(m_compositingTriggers & ChromeClient::CanvasTrigger))
-        return false;
-
-    if (renderer->isCanvas()) {
-        HTMLCanvasElement* canvas = toHTMLCanvasElement(renderer->node());
-        return canvas->renderingContext() && canvas->renderingContext()->isAccelerated();
-    }
-    return false;
-}
-
 bool CompositingReasonFinder::requiresCompositingForPlugin(RenderObject* renderer, bool* needToRecomputeCompositingRequirements) const
 {
-    if (!(m_compositingTriggers & ChromeClient::PluginTrigger))
+    if (!(m_compositingTriggers & PluginTrigger))
         return false;
 
     if (!renderer->isEmbeddedObject() || !toRenderEmbeddedObject(renderer)->allowsAcceleratedCompositing())
@@ -190,7 +159,7 @@ bool CompositingReasonFinder::requiresCompositingForFrame(RenderObject* renderer
 
 bool CompositingReasonFinder::requiresCompositingForBackfaceVisibilityHidden(RenderObject* renderer) const
 {
-    if (!(m_compositingTriggers & ChromeClient::ThreeDTransformTrigger))
+    if (!(m_compositingTriggers & ThreeDTransformTrigger))
         return false;
 
     return renderer->style()->backfaceVisibility() == BackfaceVisibilityHidden;
@@ -198,7 +167,7 @@ bool CompositingReasonFinder::requiresCompositingForBackfaceVisibilityHidden(Ren
 
 bool CompositingReasonFinder::requiresCompositingForAnimation(RenderObject* renderer) const
 {
-    if (!(m_compositingTriggers & ChromeClient::AnimationTrigger))
+    if (!(m_compositingTriggers & AnimationTrigger))
         return false;
 
     return shouldCompositeForActiveAnimations(*renderer);
@@ -206,7 +175,7 @@ bool CompositingReasonFinder::requiresCompositingForAnimation(RenderObject* rend
 
 bool CompositingReasonFinder::requiresCompositingForTransition(RenderObject* renderer) const
 {
-    if (!(m_compositingTriggers & ChromeClient::AnimationTrigger))
+    if (!(m_compositingTriggers & AnimationTrigger))
         return false;
 
     if (Settings* settings = m_renderView.document().settings()) {
@@ -221,7 +190,7 @@ bool CompositingReasonFinder::requiresCompositingForTransition(RenderObject* ren
 
 bool CompositingReasonFinder::requiresCompositingForFilters(RenderObject* renderer) const
 {
-    if (!(m_compositingTriggers & ChromeClient::FilterTrigger))
+    if (!(m_compositingTriggers & FilterTrigger))
         return false;
 
     return renderer->hasFilter();

third_party/WebKit/Source/core/rendering/compositing/CompositingReasonFinder.h

@@ -5,8 +5,8 @@
 #ifndef CompositingReasonFinder_h
 #define CompositingReasonFinder_h
 
-#include "core/page/ChromeClient.h"
 #include "core/rendering/RenderLayer.h"
+#include "core/rendering/compositing/CompositingTriggers.h"
 #include "platform/graphics/CompositingReasons.h"
 
 namespace WebCore {
@@ -38,8 +38,6 @@ private:
     bool requiresCompositingForAnimation(RenderObject*) const;
     bool requiresCompositingForTransition(RenderObject*) const;
     bool requiresCompositingForTransform(RenderObject*) const;
-    bool requiresCompositingForVideo(RenderObject*) const;
-    bool requiresCompositingForCanvas(RenderObject*) const;
     bool requiresCompositingForPlugin(RenderObject*, bool* needToRecomputeCompositingRequirements) const;
     bool requiresCompositingForFrame(RenderObject*) const;
     bool requiresCompositingForBackfaceVisibilityHidden(RenderObject*) const;
@@ -50,7 +48,7 @@ private:
     bool requiresCompositingForWillChange(const RenderObject*) const;
 
     RenderView& m_renderView;
-    ChromeClient::CompositingTriggerFlags m_compositingTriggers;
+    CompositingTriggerFlags m_compositingTriggers;
 };
 
 } // namespace WebCore

third_party/WebKit/Source/core/rendering/compositing/CompositingTriggers.h

+/*
+ * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple, Inc. All rights reserved.
+ * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
+ * Copyright (C) 2012 Samsung Electronics. All rights reserved.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public License
+ * along with this library; see the file COPYING.LIB.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifndef CompositingTriggers_h
+#define CompositingTriggers_h
+
+namespace WebCore {
+
+enum CompositingTrigger {
+    ThreeDTransformTrigger = 1 << 0,
+    VideoTrigger = 1 << 1,
+    PluginTrigger = 1 << 2,
+    CanvasTrigger = 1 << 3,
+    AnimationTrigger = 1 << 4,
+    FilterTrigger = 1 << 5,
+    ScrollableInnerFrameTrigger = 1 << 6,
+    AllCompositingTriggers = 0xFFFFFFFF
+};
+
+typedef unsigned CompositingTriggerFlags;
+
+}
+
+#endif

third_party/WebKit/Source/web/ChromeClientImpl.cpp

@@ -711,27 +711,27 @@ void ChromeClientImpl::attachRootGraphicsLayer(GraphicsLayer* rootLayer)
     m_webView->setRootGraphicsLayer(rootLayer);
 }
 
-ChromeClient::CompositingTriggerFlags ChromeClientImpl::allowedCompositingTriggers() const
+WebCore::CompositingTriggerFlags ChromeClientImpl::allowedCompositingTriggers() const
 {
     if (!m_webView->allowsAcceleratedCompositing())
         return 0;
 
-    CompositingTriggerFlags flags = 0;
+    WebCore::CompositingTriggerFlags flags = 0;
     Settings& settings = m_webView->page()->settings();
     if (settings.acceleratedCompositingFor3DTransformsEnabled())
-        flags |= ThreeDTransformTrigger;
+        flags |= WebCore::ThreeDTransformTrigger;
     if (settings.acceleratedCompositingForVideoEnabled())
-        flags |= VideoTrigger;
+        flags |= WebCore::VideoTrigger;
     if (settings.acceleratedCompositingForPluginsEnabled())
-        flags |= PluginTrigger;
+        flags |= WebCore::PluginTrigger;
     if (settings.acceleratedCompositingForAnimationEnabled())
-        flags |= AnimationTrigger;
+        flags |= WebCore::AnimationTrigger;
     if (settings.acceleratedCompositingForCanvasEnabled())
-        flags |= CanvasTrigger;
+        flags |= WebCore::CanvasTrigger;
     if (settings.acceleratedCompositingForScrollableFramesEnabled())
-        flags |= ScrollableInnerFrameTrigger;
+        flags |= WebCore::ScrollableInnerFrameTrigger;
     if (settings.acceleratedCompositingForFiltersEnabled())
-        flags |= FilterTrigger;
+        flags |= WebCore::FilterTrigger;
 
     return flags;
 }

third_party/WebKit/Source/web/ChromeClientImpl.h

@@ -148,7 +148,7 @@ public:
     // Pass 0 as the GraphicsLayer to detatch the root layer.
     virtual void attachRootGraphicsLayer(WebCore::GraphicsLayer*) OVERRIDE;
 
-    virtual CompositingTriggerFlags allowedCompositingTriggers() const OVERRIDE;
+    virtual WebCore::CompositingTriggerFlags allowedCompositingTriggers() const OVERRIDE;
 
     virtual void enterFullScreenForElement(WebCore::Element*) OVERRIDE;
     virtual void exitFullScreenForElement(WebCore::Element*) OVERRIDE;