Animations: Port ProgrammaticScrollAnimator to use compositor timelines

Source/core/page/scrolling/ScrollingCoordinator.cpp

 /*
  * Copyright (C) 2011 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 38 matching lines @@
 #include "platform/exported/WebScrollbarThemeGeometryNative.h"
 #include "platform/geometry/Region.h"
 #include "platform/geometry/TransformState.h"
 #include "platform/graphics/GraphicsLayer.h"
 #if OS(MACOSX)
 #include "platform/mac/ScrollAnimatorMac.h"
 #endif
 #include "platform/scroll/ScrollAnimator.h"
 #include "platform/scroll/ScrollbarTheme.h"
 #include "public/platform/Platform.h"
+#include "public/platform/WebCompositorAnimationTimeline.h"
 #include "public/platform/WebCompositorSupport.h"
 #include "public/platform/WebLayerPositionConstraint.h"
 #include "public/platform/WebScrollbarLayer.h"
 #include "public/platform/WebScrollbarThemeGeometry.h"
 #include "public/platform/WebScrollbarThemePainter.h"
 #include "wtf/text/StringBuilder.h"
 
 using blink::WebLayer;
 using blink::WebLayerPositionConstraint;
 using blink::WebRect;
@@ skipping 17 matching lines @@
 }
 
 ScrollingCoordinator::ScrollingCoordinator(Page* page)
     : m_page(page)
     , m_scrollGestureRegionIsDirty(false)
     , m_touchEventTargetRectsAreDirty(false)
     , m_shouldScrollOnMainThreadDirty(false)
     , m_wasFrameScrollable(false)
     , m_lastMainThreadScrollingReasons(0)
 {
+    if (RuntimeEnabledFeatures::compositorAnimationTimelinesEnabled() && Platform::current()->compositorSupport()) {

[Ian Vollick, 2015/07/10 03:06:45]

AFAICT, most of the time we assume that compositorSupport() will not return null
in blink. I do see a few call sites that do a nullity check, but looking at
render_thread_impl.cc, it looks like we EnsureWebKitInitialized at the
appropriate times to guarantee we have one. Is this check really necessary?

[loyso (OOO), 2015/07/22 05:24:23]

Done.

+        ASSERT(m_page);
+        ASSERT(m_page->mainFrame()->isLocalFrame());
+        m_programmaticScrollAnimatorTimeline = adoptPtr(Platform::current()->compositorSupport()->createAnimationTimeline());
+        m_page->chromeClient().attachCompositorAnimationTimeline(m_programmaticScrollAnimatorTimeline.get(), toLocalFrame(m_page->mainFrame()));
+    }
 }
 
 ScrollingCoordinator::~ScrollingCoordinator()
 {
     ASSERT(!m_page);
 }
 
 DEFINE_TRACE(ScrollingCoordinator)
 {
     visitor->trace(m_page);
@@ skipping 322 matching lines @@
     if (WebScrollbarLayer* scrollbarLayer = getWebScrollbarLayer(scrollableArea, VerticalScrollbar)) {
         GraphicsLayer* verticalScrollbarLayer = scrollableArea->layerForVerticalScrollbar();
         if (verticalScrollbarLayer)
             setupScrollbarLayer(verticalScrollbarLayer, scrollbarLayer, webLayer, containerLayer);
     }
 
     // Update the viewport layer registration if the outer viewport may have changed.
     if (m_page->settings().rootLayerScrolls() && isForRootLayer(scrollableArea))
         m_page->chromeClient().registerViewportLayers();
 
-    scrollableArea->layerForScrollingDidChange();
+    scrollableArea->layerForScrollingDidChange(m_programmaticScrollAnimatorTimeline.get());
 
     return !!webLayer;
 }
 
 using GraphicsLayerHitTestRects = WTF::HashMap<const GraphicsLayer*, Vector<LayoutRect>>;
 
 // In order to do a DFS cross-frame walk of the Layer tree, we need to know which
 // Layers have child frames inside of them. This computes a mapping for the
 // current frame which we can consult while walking the layers of that frame.
 // Whenever we descend into a new frame, a new map will be created.
@@ skipping 267 matching lines @@
         return;
     if (WebLayer* scrollLayer = toWebLayer(m_page->deprecatedLocalMainFrame()->view()->layerForScrolling())) {
         m_lastMainThreadScrollingReasons = reasons;
         scrollLayer->setShouldScrollOnMainThread(reasons);
     }
 }
 
 void ScrollingCoordinator::willBeDestroyed()
 {
     ASSERT(m_page);
+
+    if (m_programmaticScrollAnimatorTimeline) {
+        ASSERT(m_page->mainFrame()->isLocalFrame());
+        m_page->chromeClient().detachCompositorAnimationTimeline(m_programmaticScrollAnimatorTimeline.get(), toLocalFrame(m_page->mainFrame()));
+        m_programmaticScrollAnimatorTimeline.clear();
+    }
+
     m_page = nullptr;
     for (const auto& scrollbar : m_horizontalScrollbars)
         GraphicsLayer::unregisterContentsLayer(scrollbar.value->layer());
     for (const auto& scrollbar : m_verticalScrollbars)
         GraphicsLayer::unregisterContentsLayer(scrollbar.value->layer());
 }
 
 bool ScrollingCoordinator::coordinatesScrollingForFrameView(FrameView* frameView) const
 {
     ASSERT(isMainThread());
@@ skipping 325 matching lines @@
     bool frameIsScrollable = frameView && frameView->isScrollable();
     if (frameIsScrollable != m_wasFrameScrollable)
         return true;
 
     if (WebLayer* scrollLayer = frameView ? toWebLayer(frameView->layerForScrolling()) : nullptr)
         return WebSize(frameView->contentsSize()) != scrollLayer->bounds();
     return false;
 }
 
 } // namespace blink