Use const ref for LocalFrame::LocalFrameRoot and FrameTree::Top

third_party/WebKit/Source/core/frame/FrameView.cpp

 /*
  * Copyright (C) 1998, 1999 Torben Weis <weis@kde.org>
  *                     1999 Lars Knoll <knoll@kde.org>
  *                     1999 Antti Koivisto <koivisto@kde.org>
  *                     2000 Dirk Mueller <mueller@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
  *           (C) 2006 Graham Dennis (graham.dennis@gmail.com)
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
@@ skipping 589 matching lines @@
 ScrollingCoordinator* FrameView::GetScrollingCoordinator() const {
   Page* p = GetPage();
   return p ? p->GetScrollingCoordinator() : 0;
 }
 
 CompositorAnimationHost* FrameView::GetCompositorAnimationHost() const {
   // When m_animationHost is not nullptr, this is the FrameView for an OOPIF.
   if (animation_host_)
     return animation_host_.get();
 
-  if (frame_->LocalFrameRoot() != frame_)
-    return frame_->LocalFrameRoot()->View()->GetCompositorAnimationHost();
+  if (&frame_->LocalFrameRoot() != frame_)
+    return frame_->LocalFrameRoot().View()->GetCompositorAnimationHost();
 
   if (!frame_->IsMainFrame())
     return nullptr;
 
   ScrollingCoordinator* c = GetScrollingCoordinator();
   return c ? c->GetCompositorAnimationHost() : nullptr;
 }
 
 CompositorAnimationTimeline* FrameView::GetCompositorAnimationTimeline() const {
   if (animation_timeline_)
     return animation_timeline_.get();
 
-  if (frame_->LocalFrameRoot() != frame_)
-    return frame_->LocalFrameRoot()->View()->GetCompositorAnimationTimeline();
+  if (&frame_->LocalFrameRoot() != frame_)
+    return frame_->LocalFrameRoot().View()->GetCompositorAnimationTimeline();
 
   if (!frame_->IsMainFrame())
     return nullptr;
 
   ScrollingCoordinator* c = GetScrollingCoordinator();
   return c ? c->GetCompositorAnimationTimeline() : nullptr;
 }
 
 LayoutBox* FrameView::GetLayoutBox() const {
   return GetLayoutView();
@@ skipping 1486 matching lines @@
   if (local_frame && ComputeCompositedSelection(*local_frame, selection)) {
     page->GetChromeClient().UpdateCompositedSelection(local_frame, selection);
   } else {
     if (!local_frame) {
       // Clearing the mainframe when there is no focused frame (and hence
       // no localFrame) is legacy behaviour, and implemented here to
       // satisfy ParameterizedWebFrameTest.CompositedSelectionBoundsCleared's
       // first check that the composited selection has been cleared even
       // though no frame has focus yet. If this is not desired, then the
       // expectation needs to be removed from the test.
-      local_frame = frame_->LocalFrameRoot();
+      local_frame = &frame_->LocalFrameRoot();
     }
 
     if (local_frame)
       page->GetChromeClient().ClearCompositedSelection(local_frame);
   }
 }
 
 PlatformChromeClient* FrameView::GetChromeClient() const {
   Page* page = GetFrame().GetPage();
   if (!page)
@@ skipping 418 matching lines @@
 
   frame_->Selection().DidLayout();
 
   ASSERT(frame_->GetDocument());
 
   FontFaceSet::DidLayout(*frame_->GetDocument());
   // Cursor update scheduling is done by the local root, which is the main frame
   // if there are no RemoteFrame ancestors in the frame tree. Use of
   // localFrameRoot() is discouraged but will change when cursor update
   // scheduling is moved from EventHandler to PageEventHandler.
-  GetFrame().LocalFrameRoot()->GetEventHandler().ScheduleCursorUpdate();
+  GetFrame().LocalFrameRoot().GetEventHandler().ScheduleCursorUpdate();
 
   UpdateGeometries();
 
   // Plugins could have torn down the page inside updateGeometries().
   if (GetLayoutViewItem().IsNull())
     return;
 
   ScheduleUpdatePluginsIfNecessary();
 
   if (ScrollingCoordinator* scrolling_coordinator =
@@ skipping 362 matching lines @@
 void FrameView::UpdateGeometriesIfNeeded() {
   if (!needs_update_geometries_)
     return;
 
   needs_update_geometries_ = false;
 
   UpdateGeometries();
 }
 
 void FrameView::UpdateAllLifecyclePhases() {
-  GetFrame().LocalFrameRoot()->View()->UpdateLifecyclePhasesInternal(
+  GetFrame().LocalFrameRoot().View()->UpdateLifecyclePhasesInternal(
       DocumentLifecycle::kPaintClean);
 }
 
 // TODO(chrishtr): add a scrolling update lifecycle phase.
 void FrameView::UpdateLifecycleToCompositingCleanPlusScrolling() {
   if (RuntimeEnabledFeatures::slimmingPaintV2Enabled()) {
     UpdateAllLifecyclePhasesExceptPaint();
   } else {
-    GetFrame().LocalFrameRoot()->View()->UpdateLifecyclePhasesInternal(
+    GetFrame().LocalFrameRoot().View()->UpdateLifecyclePhasesInternal(
         DocumentLifecycle::kCompositingClean);
   }
 }
 
 void FrameView::UpdateLifecycleToCompositingInputsClean() {
   // When SPv2 is enabled, the standard compositing lifecycle steps do not
   // exist; compositing is done after paint instead.
   DCHECK(!RuntimeEnabledFeatures::slimmingPaintV2Enabled());
-  GetFrame().LocalFrameRoot()->View()->UpdateLifecyclePhasesInternal(
+  GetFrame().LocalFrameRoot().View()->UpdateLifecyclePhasesInternal(
       DocumentLifecycle::kCompositingInputsClean);
 }
 
 void FrameView::UpdateAllLifecyclePhasesExceptPaint() {
-  GetFrame().LocalFrameRoot()->View()->UpdateLifecyclePhasesInternal(
+  GetFrame().LocalFrameRoot().View()->UpdateLifecyclePhasesInternal(
       DocumentLifecycle::kPrePaintClean);
 }
 
 void FrameView::UpdateLifecycleToLayoutClean() {
-  GetFrame().LocalFrameRoot()->View()->UpdateLifecyclePhasesInternal(
+  GetFrame().LocalFrameRoot().View()->UpdateLifecyclePhasesInternal(
       DocumentLifecycle::kLayoutClean);
 }
 
 void FrameView::ScheduleVisualUpdateForPaintInvalidationIfNeeded() {
-  LocalFrame* local_frame_root = GetFrame().LocalFrameRoot();
-  if (local_frame_root->View()->current_update_lifecycle_phases_target_state_ <
+  LocalFrame& local_frame_root = GetFrame().LocalFrameRoot();
+  if (local_frame_root.View()->current_update_lifecycle_phases_target_state_ <
           DocumentLifecycle::kPaintInvalidationClean ||
       Lifecycle().GetState() >= DocumentLifecycle::kPrePaintClean) {
     // Schedule visual update to process the paint invalidation in the next
     // cycle.
-    local_frame_root->ScheduleVisualUpdateUnlessThrottled();
+    local_frame_root.ScheduleVisualUpdateUnlessThrottled();
   }
   // Otherwise the paint invalidation will be handled in paint invalidation
   // phase of this cycle.
 }
 
 void FrameView::NotifyResizeObservers() {
   // Controller exists only if ResizeObserver was created.
   if (!GetFrame().GetDocument()->GetResizeObserverController())
     return;
 
@@ skipping 145 matching lines @@
 
       if (target_state >= DocumentLifecycle::kPrePaintClean) {
         if (!RuntimeEnabledFeatures::slimmingPaintInvalidationEnabled())
           InvalidateTreeIfNeededRecursive();
 
         if (!RuntimeEnabledFeatures::slimmingPaintV2Enabled()) {
           if (view.Compositor()->InCompositingMode())
             GetScrollingCoordinator()->UpdateAfterCompositingChangeIfNeeded();
         }
 
-        if (LocalFrame* local_frame = frame_->LocalFrameRoot()) {
-          // This is needed since, at present, the ScrollingCoordinator doesn't
-          // send rects for oopif sub-frames.
-          // TODO(wjmaclean): Remove this pathway when ScrollingCoordinator
-          // operates on a per-frame basis. https://crbug.com/680606
-          GetFrame()
-              .GetPage()
-              ->GetChromeClient()
-              .UpdateEventRectsForSubframeIfNecessary(local_frame);
-        }
+        // This is needed since, at present, the ScrollingCoordinator doesn't
+        // send rects for oopif sub-frames.
+        // TODO(wjmaclean): Remove this pathway when ScrollingCoordinator
+        // operates on a per-frame basis. https://crbug.com/680606
+        GetFrame()
+            .GetPage()
+            ->GetChromeClient()
+            .UpdateEventRectsForSubframeIfNecessary(&frame_->LocalFrameRoot());
         UpdateCompositedSelectionIfNeeded();
       }
 
       // TODO(pdr): prePaint should be under the "Paint" devtools timeline step
       // for slimming paint v2.
       if (target_state >= DocumentLifecycle::kPrePaintClean)
         PrePaint();
     }
 
     if (target_state == DocumentLifecycle::kPaintClean) {
@@ skipping 173 matching lines @@
   paint_artifact_compositor_->Update(
       paint_controller_->GetPaintArtifact(),
       paint_controller_->PaintChunksRasterInvalidationTrackingMap(),
       is_storing_composited_layer_debug_info_, composited_element_ids);
 }
 
 std::unique_ptr<JSONObject> FrameView::CompositedLayersAsJSON(
     LayerTreeFlags flags) {
   return GetFrame()
       .LocalFrameRoot()
-      ->View()
+      .View()
       ->paint_artifact_compositor_->LayersAsJSON(flags);
 }
 
 void FrameView::UpdateStyleAndLayoutIfNeededRecursive() {
   SCOPED_BLINK_UMA_HISTOGRAM_TIMER("Blink.StyleAndLayout.UpdateTime");
   UpdateStyleAndLayoutIfNeededRecursiveInternal();
 }
 
 void FrameView::UpdateStyleAndLayoutIfNeededRecursiveInternal() {
   if (ShouldThrottleRendering() || !frame_->GetDocument()->IsActive())
@@ skipping 358 matching lines @@
 
 void FrameView::SetInitialTracksPaintInvalidationsForTesting(
     bool track_paint_invalidations) {
   g_initial_track_all_paint_invalidations = track_paint_invalidations;
 }
 
 void FrameView::SetTracksPaintInvalidations(bool track_paint_invalidations) {
   if (track_paint_invalidations == IsTrackingPaintInvalidations())
     return;
 
-  for (Frame* frame = frame_->Tree().Top(); frame;
+  for (Frame* frame = &frame_->Tree().Top(); frame;
        frame = frame->Tree().TraverseNext()) {
     if (!frame->IsLocalFrame())
       continue;
     if (LayoutViewItem layout_view = ToLocalFrame(frame)->ContentLayoutItem()) {
       layout_view.GetFrameView()->tracked_object_paint_invalidations_ =
           WTF::WrapUnique(track_paint_invalidations
                               ? new Vector<ObjectPaintInvalidation>
                               : nullptr);
       if (RuntimeEnabledFeatures::slimmingPaintV2Enabled()) {
         paint_controller_->SetTracksRasterInvalidations(
@@ skipping 21 matching lines @@
   ObjectPaintInvalidation invalidation = {client.DebugName(), reason};
   tracked_object_paint_invalidations_->push_back(invalidation);
 }
 
 std::unique_ptr<JSONArray> FrameView::TrackedObjectPaintInvalidationsAsJSON()
     const {
   if (!tracked_object_paint_invalidations_)
     return nullptr;
 
   std::unique_ptr<JSONArray> result = JSONArray::Create();
-  for (Frame* frame = frame_->Tree().Top(); frame;
+  for (Frame* frame = &frame_->Tree().Top(); frame;
        frame = frame->Tree().TraverseNext()) {
     if (!frame->IsLocalFrame())
       continue;
     if (LayoutViewItem layout_view = ToLocalFrame(frame)->ContentLayoutItem()) {
       if (!layout_view.GetFrameView()->tracked_object_paint_invalidations_)
         continue;
       for (const auto& item :
            *layout_view.GetFrameView()->tracked_object_paint_invalidations_) {
         std::unique_ptr<JSONObject> item_json = JSONObject::Create();
         item_json->SetString("object", item.name);
@@ skipping 1479 matching lines @@
   if (!GetPage()->GetSettings().GetThreadedScrollingEnabled())
     reasons |= MainThreadScrollingReason::kThreadedScrollingDisabled;
 
   if (!GetPage()->MainFrame()->IsLocalFrame())
     return reasons;
 
   // TODO(alexmos,kenrb): For OOPIF, local roots that are different from
   // the main frame can't be used in the calculation, since they use
   // different compositors with unrelated state, which breaks some of the
   // calculations below.
-  if (frame_->LocalFrameRoot() != GetPage()->MainFrame())
+  if (&frame_->LocalFrameRoot() != GetPage()->MainFrame())
     return reasons;
 
   // Walk the tree to the root. Use the gathered reasons to determine
   // whether the target frame should be scrolled on main thread regardless
   // other subframes on the same page.
   for (Frame* frame = frame_; frame; frame = frame->Tree().Parent()) {
     if (!frame->IsLocalFrame())
       continue;
     reasons |=
         ToLocalFrame(frame)->View()->MainThreadScrollingReasonsPerFrame();
@@ skipping 56 matching lines @@
       FloatQuad(FloatRect(rect)), ancestor, mode);
   rect = LayoutRect(mapped_quad.BoundingBox());
 
   // localToAncestorQuad accounts for scroll offset if it encounters a remote
   // frame in the ancestor chain, otherwise it needs to be added explicitly.
   if (GetFrame().LocalFrameRoot() == GetFrame().Tree().Top() ||
       (ancestor &&
        ancestor->GetFrame()->LocalFrameRoot() == GetFrame().LocalFrameRoot())) {
     FrameView* ancestor_view =
         (ancestor ? ancestor->GetFrameView()
-                  : ToLocalFrame(GetFrame().Tree().Top())->View());
+                  : ToLocalFrame(GetFrame().Tree().Top()).View());
     LayoutSize scroll_position = LayoutSize(ancestor_view->GetScrollOffset());
     rect.Move(-scroll_position);
   }
 }
 
 bool FrameView::MapToVisualRectInTopFrameSpace(LayoutRect& rect) {
   // This is the top-level frame, so no mapping necessary.
   if (frame_->IsMainFrame())
     return true;
 
@@ skipping 23 matching lines @@
 void FrameView::SetAnimationHost(
     std::unique_ptr<CompositorAnimationHost> host) {
   animation_host_ = std::move(host);
 }
 
 LayoutUnit FrameView::CaretWidth() const {
   return LayoutUnit(GetChromeClient()->WindowToViewportScalar(1));
 }
 
 }  // namespace blink