Move logic of recording main thread scrolling reasons from cc to blink::ScrollManager

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

Index: third_party/WebKit/Source/core/frame/FrameView.cpp
diff --git a/third_party/WebKit/Source/core/frame/FrameView.cpp b/third_party/WebKit/Source/core/frame/FrameView.cpp
index b1d02ace0ffb01dbc2ba7b3a91873001b71fb05a..6ad835a489e1b20dd0c109aa97f949a4cc3c01a6 100644
--- a/third_party/WebKit/Source/core/frame/FrameView.cpp
+++ b/third_party/WebKit/Source/core/frame/FrameView.cpp
@@ -203,10 +203,7 @@ FrameView::FrameView(LocalFrame& frame)
       m_needsScrollbarsUpdate(false),
       m_suppressAdjustViewSize(false),
       m_allowsLayoutInvalidationAfterLayoutClean(true),
-      m_mainThreadScrollingReasons(0),
-      m_mainThreadScrollingReasonsCounter(
-          MainThreadScrollingReason::kMainThreadScrollingReasonCount,
-          0) {
+      m_mainThreadScrollingReasons(0) {
   init();
 }
 
@@ -5090,6 +5087,8 @@ void FrameView::updateSubFrameScrollOnMainReason(
 
   if (frame.isMainFrame())
     m_mainThreadScrollingReasons = reasons;
+  DCHECK(!MainThreadScrollingReason::NonCompositedScrollReasons(
+      m_mainThreadScrollingReasons));
 }
 
 MainThreadScrollingReasons FrameView::mainThreadScrollingReasonsPerFrame()
@@ -5148,6 +5147,7 @@ MainThreadScrollingReasons FrameView::mainThreadScrollingReasons() const {
         toLocalFrame(frame)->view()->mainThreadScrollingReasonsPerFrame();
   }
 
+  DCHECK(!MainThreadScrollingReason::NonCompositedScrollReasons(reasons));
   return reasons;
 }
 
@@ -5180,29 +5180,6 @@ String FrameView::mainThreadScrollingReasonsAsText() const {
   return result;
 }
 
-void FrameView::adjustStyleRelatedMainThreadScrollingReasons(
-    const uint32_t reason,
-    bool increase) {
-  int index = MainThreadScrollingReason::getReasonIndex(reason);
-  DCHECK_GE(index, 0);
-  m_mainThreadScrollingReasonsCounter[index] += increase ? 1 : -1;
-  DCHECK_GE(m_mainThreadScrollingReasonsCounter[index], 0);
-}
-
-MainThreadScrollingReasons
-FrameView::getStyleRelatedMainThreadScrollingReasons() const {
-  MainThreadScrollingReasons reasons =
-      static_cast<MainThreadScrollingReasons>(0);
-  for (uint32_t reason = 0;
-       reason < MainThreadScrollingReason::kMainThreadScrollingReasonCount;
-       ++reason) {
-    if (m_mainThreadScrollingReasonsCounter[reason] > 0) {
-      reasons |= 1 << reason;
-    }
-  }
-  return reasons;
-}
-
 void FrameView::setViewportIntersectionFromParent(
     const IntRect& viewportIntersection) {
   if (m_remoteViewportIntersection != viewportIntersection) {