Add a new document lifecycle; CompositingInputsClean

third_party/WebKit/Source/core/layout/compositing/PaintLayerCompositor.cpp

Index: third_party/WebKit/Source/core/layout/compositing/PaintLayerCompositor.cpp
diff --git a/third_party/WebKit/Source/core/layout/compositing/PaintLayerCompositor.cpp b/third_party/WebKit/Source/core/layout/compositing/PaintLayerCompositor.cpp
index 5d639a1d6945e3b112569310f6e9319609b3aaf0..a2c8addbdb6ca334bdde9212a6230e87a1edeeaa 100644
--- a/third_party/WebKit/Source/core/layout/compositing/PaintLayerCompositor.cpp
+++ b/third_party/WebKit/Source/core/layout/compositing/PaintLayerCompositor.cpp
@@ -184,12 +184,16 @@ static LayoutVideo* FindFullscreenVideoLayoutObject(Document& document) {
   return ToLayoutVideo(layout_object);
 }
 
-void PaintLayerCompositor::UpdateIfNeededRecursive() {
+void PaintLayerCompositor::UpdateIfNeededRecursive(
+    DocumentLifecycle::LifecycleState target_state) {
   SCOPED_BLINK_UMA_HISTOGRAM_TIMER("Blink.Compositing.UpdateTime");
-  UpdateIfNeededRecursiveInternal();
+  UpdateIfNeededRecursiveInternal(target_state);
 }
 
-void PaintLayerCompositor::UpdateIfNeededRecursiveInternal() {
+void PaintLayerCompositor::UpdateIfNeededRecursiveInternal(
+    DocumentLifecycle::LifecycleState target_state) {
+  DCHECK(target_state >= DocumentLifecycle::kCompositingInputsClean);
+
   FrameView* view = layout_view_.GetFrameView();
   if (view->ShouldThrottleRendering())
     return;
@@ -205,10 +209,11 @@ void PaintLayerCompositor::UpdateIfNeededRecursiveInternal() {
     // the middle of frame detach.
     // TODO(bbudge) Remove this check when trusted Pepper plugins are gone.
     if (local_frame->GetDocument()->IsActive() &&
-        !local_frame->ContentLayoutItem().IsNull())
+        !local_frame->ContentLayoutItem().IsNull()) {
       local_frame->ContentLayoutItem()
           .Compositor()
-          ->UpdateIfNeededRecursiveInternal();
+          ->UpdateIfNeededRecursiveInternal(target_state);
+    }
   }
 
   TRACE_EVENT0("blink", "PaintLayerCompositor::updateIfNeededRecursive");
@@ -226,9 +231,11 @@ void PaintLayerCompositor::UpdateIfNeededRecursiveInternal() {
 
   layout_view_.CommitPendingSelection();
 
-  Lifecycle().AdvanceTo(DocumentLifecycle::kInCompositingUpdate);
-  UpdateIfNeeded();
-  Lifecycle().AdvanceTo(DocumentLifecycle::kCompositingClean);
+  UpdateIfNeeded(target_state);
+  DCHECK(Lifecycle().GetState() == DocumentLifecycle::kCompositingInputsClean ||
+         Lifecycle().GetState() == DocumentLifecycle::kCompositingClean);
+  if (target_state == DocumentLifecycle::kCompositingInputsClean)
+    return;
 
   Optional<CompositorElementIdSet> composited_element_ids;
   DocumentAnimations::UpdateAnimations(layout_view_.GetDocument(),
@@ -371,17 +378,27 @@ GraphicsLayer* PaintLayerCompositor::ParentForContentLayers() const {
   return IsMainFrame() ? GetVisualViewport().ScrollLayer() : nullptr;
 }
 
-void PaintLayerCompositor::UpdateIfNeeded() {
+void PaintLayerCompositor::UpdateIfNeeded(
+    DocumentLifecycle::LifecycleState target_state) {
+  DCHECK(target_state >= DocumentLifecycle::kCompositingInputsClean);
+
+  Lifecycle().AdvanceTo(DocumentLifecycle::kInCompositingUpdate);
+
   CompositingUpdateType update_type = pending_update_type_;
   pending_update_type_ = kCompositingUpdateNone;
 
   if (!HasAcceleratedCompositing()) {
     UpdateWithoutAcceleratedCompositing(update_type);
+    Lifecycle().AdvanceTo(
+        std::min(DocumentLifecycle::kCompositingClean, target_state));
     return;
   }
 
-  if (update_type == kCompositingUpdateNone)
+  if (update_type == kCompositingUpdateNone) {
+    Lifecycle().AdvanceTo(
+        std::min(DocumentLifecycle::kCompositingClean, target_state));
     return;
+  }
 
   PaintLayer* update_root = RootLayer();
 
@@ -396,6 +413,16 @@ void PaintLayerCompositor::UpdateIfNeeded() {
         update_root);
 #endif
 
+    // In the case where we only want to make compositing inputs clean, we
+    // early-exit here. Because we have not handled the other implications of
+    // |pending_update_type_| > kCompositingUpdateNone, we must restore the
+    // pending update type for a future call.
+    if (target_state == DocumentLifecycle::kCompositingInputsClean) {
+      pending_update_type_ = update_type;
+      Lifecycle().AdvanceTo(DocumentLifecycle::kCompositingInputsClean);
+      return;
+    }
+
     CompositingRequirementsUpdater(layout_view_, compositing_reason_finder_)
         .Update(update_root);
 
@@ -422,6 +449,15 @@ void PaintLayerCompositor::UpdateIfNeeded() {
     }
   }
 
+  // If we hit this check then we were asked to only make compositing inputs
+  // clean but they were already clean. Therefore the correct behavior is to
+  // just restore the pending state and exit.
+  if (target_state == DocumentLifecycle::kCompositingInputsClean) {

[flackr, 2017/04/12 15:50:15]

I think this early exit would be cleaner at the top of the function before we
replace the pending_update_type_, i.e. if update_type <
kCompositingUpdateAfterCompositingInputChange.

[smcgruer, 2017/04/12 17:18:44]

Done.

+    pending_update_type_ = update_type;
+    Lifecycle().AdvanceTo(DocumentLifecycle::kCompositingInputsClean);
+    return;
+  }
+
   if (RuntimeEnabledFeatures::compositorWorkerEnabled() && scroll_layer_) {
     // If rootLayerScrolls is enabled, these properties are applied in
     // CompositedLayerMapping::updateElementIdAndCompositorMutableProperties.
@@ -488,6 +524,8 @@ void PaintLayerCompositor::UpdateIfNeeded() {
   // Inform the inspector that the layer tree has changed.
   if (IsMainFrame())
     probe::layerTreeDidChange(layout_view_.GetFrame());
+
+  Lifecycle().AdvanceTo(DocumentLifecycle::kCompositingClean);
 }
 
 static void RestartAnimationOnCompositor(const LayoutObject& layout_object) {