Rename ScrollType helper and combine some redundant checks.

third_party/WebKit/Source/platform/scroll/ScrollTypes.h

Index: third_party/WebKit/Source/platform/scroll/ScrollTypes.h
diff --git a/third_party/WebKit/Source/platform/scroll/ScrollTypes.h b/third_party/WebKit/Source/platform/scroll/ScrollTypes.h
index 139f88bd51a6365c8e870fea06193d2713ceab4d..8971c625bc9a2faa97c32856ce65130ac0704f7e 100644
--- a/third_party/WebKit/Source/platform/scroll/ScrollTypes.h
+++ b/third_party/WebKit/Source/platform/scroll/ScrollTypes.h
@@ -79,7 +79,9 @@ enum ScrollType {
   kAnchoringScroll
 };
 
-inline bool ScrollTypeClearsFragmentAnchor(ScrollType scroll_type) {
+// An explicit scroll is one that was requested by the user or the webpage.
+// An implicit scroll is a side effect of a layout change.
+inline bool IsExplicitScrollType(ScrollType scroll_type) {
   return scroll_type == kUserScroll || scroll_type == kProgrammaticScroll ||
          scroll_type == kCompositorScroll;
 }