Refactor UpdateLifecyclePhasesInternal.

This patch splits ups the four major components of lifecycle updates:
- Style and layout
- Compositing
- PrePaint
- Paint

into separate functions, named similarly to indicate that they are a
part of lifecycle updates.

It also separates various checks and state set up to be in a wrapper
function around UpdateLifecyclePhasesInternal to ensure that the
lifecycle updates themselves are easy to follow.

Also adds comments throughout.

R=chrishtr@chromium.org

Change-Id: I5fb23bd48757866bdb42e49b6d35fa99fa9f8d41
Reviewed-on: https://chromium-review.googlesource.com/1136882
Commit-Queue: vmpstr <vmpstr@chromium.org>
Reviewed-by: Chris Harrelson <chrishtr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#579116}

third_party/blink/renderer/core/frame/local_frame_view.h

@@ -655,6 +655,34 @@ class CORE_EXPORT LocalFrameView final
   void NotifyFrameRectsChangedIfNeeded();
 
  private:
+#if DCHECK_IS_ON()
+  class DisallowLayoutInvalidationScope {
+   public:
+    DisallowLayoutInvalidationScope(LocalFrameView* view)
+        : local_frame_view_(view) {
+      local_frame_view_->allows_layout_invalidation_after_layout_clean_ = false;
+      local_frame_view_->ForAllChildLocalFrameViews(
+          [](LocalFrameView& frame_view) {
+            if (!frame_view.ShouldThrottleRendering())
+              frame_view.CheckDoesNotNeedLayout();
+            frame_view.allows_layout_invalidation_after_layout_clean_ = false;
+          });
+    }
+    ~DisallowLayoutInvalidationScope() {
+      local_frame_view_->allows_layout_invalidation_after_layout_clean_ = true;
+      local_frame_view_->ForAllChildLocalFrameViews(
+          [](LocalFrameView& frame_view) {
+            if (!frame_view.ShouldThrottleRendering())
+              frame_view.CheckDoesNotNeedLayout();
+            frame_view.allows_layout_invalidation_after_layout_clean_ = true;
+          });
+    }
+
+   private:
+    UntracedMember<LocalFrameView> local_frame_view_;
+  };
+#endif
+
   explicit LocalFrameView(LocalFrame&, IntRect);
 
   void PaintInternal(GraphicsContext&,
@@ -669,10 +697,24 @@ class CORE_EXPORT LocalFrameView final
   void SetupPrintContext();
   void ClearPrintContext();
 
-  // Returns whethre the lifecycle was succesfully updated to the
+  // Returns whether the lifecycle was succesfully updated to the
   // target state.
-  bool UpdateLifecyclePhasesInternal(
+  bool UpdateLifecyclePhases(DocumentLifecycle::LifecycleState target_state);
+  // The internal version that does the work after the proper context and checks
+  // have passed in the above function call.
+  void UpdateLifecyclePhasesInternal(
+      DocumentLifecycle::LifecycleState target_state);
+  // Four lifecycle phases helper functions corresponding to StyleAndLayout,
+  // Compositing, PrePaint, and Paint phases. If the return value is true, it
+  // means further lifecycle phases need to be run. This is used to abort
+  // earlier if we don't need to run future lifecycle phases.
+  bool RunStyleAndLayoutLifecyclePhases(
       DocumentLifecycle::LifecycleState target_state);
+  bool RunCompositingLifecyclePhase(
+      DocumentLifecycle::LifecycleState target_state);
+  bool RunPrePaintLifecyclePhase(
+      DocumentLifecycle::LifecycleState target_state);
+  void RunPaintLifecyclePhase();
 
   void NotifyFrameRectsChangedIfNeededRecursive();
   void UpdateStyleAndLayoutIfNeededRecursive();
@@ -867,8 +909,11 @@ class CORE_EXPORT LocalFrameView final
   AnchoringAdjustmentQueue anchoring_adjustment_queue_;
 
   bool suppress_adjust_view_size_;
-  bool allows_layout_invalidation_after_layout_clean_;
-
+#if DCHECK_IS_ON()
+  // In DCHECK on builds, this is set to false when we're running lifecycle
+  // phases past layout to ensure that phases after layout don't dirty layout.
+  bool allows_layout_invalidation_after_layout_clean_ = true;
+#endif
   IntersectionObservationState intersection_observation_state_;
   bool needs_forced_compositing_update_;