Always enable warn-raw-ptr's check of raw heap pointers.

tools/clang/blink_gc_plugin/CheckFieldsVisitor.h

Index: tools/clang/blink_gc_plugin/CheckFieldsVisitor.h
diff --git a/tools/clang/blink_gc_plugin/CheckFieldsVisitor.h b/tools/clang/blink_gc_plugin/CheckFieldsVisitor.h
index 5264572be0f881f413ac9d64b773adfa6819d650..d700be2ae0201fc78f49389721580da92daad116 100644
--- a/tools/clang/blink_gc_plugin/CheckFieldsVisitor.h
+++ b/tools/clang/blink_gc_plugin/CheckFieldsVisitor.h
@@ -22,10 +22,8 @@ class CheckFieldsVisitor : public RecursiveEdgeVisitor {
  public:
   enum Error {
     kRawPtrToGCManaged,
-    kRawPtrToGCManagedWarning,
     kRefPtrToGCManaged,
     kReferencePtrToGCManaged,
-    kReferencePtrToGCManagedWarning,
     kOwnPtrToGCManaged,
     kMemberToGCUnmanaged,
     kMemberInUnmanaged,
@@ -45,10 +43,6 @@ class CheckFieldsVisitor : public RecursiveEdgeVisitor {
   void AtValue(Value* edge) override;
   void AtCollection(Collection* edge) override;
 
-  static bool IsWarning(Error error);
-  static bool IsRawPtrError(Error error);
-  static bool IsReferencePtrError(Error error);
-
  private:
   Error InvalidSmartPtr(Edge* ptr);