Revert of GC plugin: consider references equal to raw pointers.

tools/clang/blink_gc_plugin/BlinkGCPlugin.cpp

Index: tools/clang/blink_gc_plugin/BlinkGCPlugin.cpp
diff --git a/tools/clang/blink_gc_plugin/BlinkGCPlugin.cpp b/tools/clang/blink_gc_plugin/BlinkGCPlugin.cpp
index c02a4e81b53670b23d5d7e985947709164af13a5..7f61bc4f8f1647836b65a51118a2d9bdc4426ac8 100644
--- a/tools/clang/blink_gc_plugin/BlinkGCPlugin.cpp
+++ b/tools/clang/blink_gc_plugin/BlinkGCPlugin.cpp
@@ -67,10 +67,6 @@
 
 const char kRefPtrToGCManagedClassNote[] =
     "[blink-gc] RefPtr field %0 to a GC managed class declared here:";
-
-const char kReferencePtrToGCManagedClassNote[] =
-    "[blink-gc] Reference pointer field %0 to a GC managed class"
-    " declared here:";
 
 const char kOwnPtrToGCManagedClassNote[] =
     "[blink-gc] OwnPtr field %0 to a GC managed class declared here:";
@@ -857,8 +853,6 @@
     kRawPtrToGCManaged,
     kRawPtrToGCManagedWarning,
     kRefPtrToGCManaged,
-    kReferencePtrToGCManaged,
-    kReferencePtrToGCManagedWarning,
     kOwnPtrToGCManaged,
     kMemberToGCUnmanaged,
     kMemberInUnmanaged,
@@ -950,13 +944,8 @@
         return;
       }
       if (options_.warn_raw_ptr && Parent()->IsRawPtr()) {
-        if (static_cast<RawPtr*>(Parent())->HasReferenceType()) {
-          invalid_fields_.push_back(std::make_pair(
-              current_, kReferencePtrToGCManagedWarning));
-        } else {
-          invalid_fields_.push_back(std::make_pair(
-              current_, kRawPtrToGCManagedWarning));
-        }
+        invalid_fields_.push_back(std::make_pair(
+            current_, kRawPtrToGCManagedWarning));
       }
       return;
     }
@@ -973,32 +962,10 @@
       invalid_fields_.push_back(std::make_pair(current_, kOwnPtrToGCManaged));
   }
 
-  static bool IsWarning(Error error) {
-    if (error == kRawPtrToGCManagedWarning)
-      return true;
-    if (error == kReferencePtrToGCManagedWarning)
-      return true;
-    return false;
-  }
-
-  static bool IsRawPtrError(Error error) {
-    return error == kRawPtrToGCManaged ||
-        error == kRawPtrToGCManagedWarning;
-  }
-
-  static bool IsReferencePtrError(Error error) {
-    return error == kReferencePtrToGCManaged ||
-        error == kReferencePtrToGCManagedWarning;
-  }
-
  private:
   Error InvalidSmartPtr(Edge* ptr) {
-    if (ptr->IsRawPtr()) {
-      if (static_cast<RawPtr*>(ptr)->HasReferenceType())
-        return kReferencePtrToGCManaged;
-      else
-        return kRawPtrToGCManaged;
-    }
+    if (ptr->IsRawPtr())
+      return kRawPtrToGCManaged;
     if (ptr->IsRefPtr())
       return kRefPtrToGCManaged;
     if (ptr->IsOwnPtr())
@@ -1110,8 +1077,6 @@
         DiagnosticsEngine::Note, kRawPtrToGCManagedClassNote);
     diag_ref_ptr_to_gc_managed_class_note_ = diagnostic_.getCustomDiagID(
         DiagnosticsEngine::Note, kRefPtrToGCManagedClassNote);
-    diag_reference_ptr_to_gc_managed_class_note_ = diagnostic_.getCustomDiagID(
-        DiagnosticsEngine::Note, kReferencePtrToGCManagedClassNote);
     diag_own_ptr_to_gc_managed_class_note_ = diagnostic_.getCustomDiagID(
         DiagnosticsEngine::Note, kOwnPtrToGCManagedClassNote);
     diag_member_to_gc_unmanaged_class_note_ = diagnostic_.getCustomDiagID(
@@ -1662,9 +1627,7 @@
         json_->Write("loc", loc);
         json_->Write("ptr",
                      !Parent() ? "val" :
-                     Parent()->IsRawPtr() ?
-                         (static_cast<RawPtr*>(Parent())->HasReferenceType() ?
-                             "reference" : "raw") :
+                     Parent()->IsRawPtr() ? "raw" :
                      Parent()->IsRefPtr() ? "ref" :
                      Parent()->IsOwnPtr() ? "own" :
                      (Parent()->IsMember() ||
@@ -1875,7 +1838,7 @@
     for (CheckFieldsVisitor::Errors::iterator it = errors->begin();
          only_warnings && it != errors->end();
          ++it) {
-      if (!CheckFieldsVisitor::IsWarning(it->second))
+      if (it->second != CheckFieldsVisitor::kRawPtrToGCManagedWarning)
         only_warnings = false;
     }
     diagnostic_.Report(full_loc, only_warnings ?
@@ -1886,10 +1849,9 @@
          it != errors->end();
          ++it) {
       unsigned error;
-      if (CheckFieldsVisitor::IsRawPtrError(it->second)) {
+      if (it->second == CheckFieldsVisitor::kRawPtrToGCManaged ||
+          it->second == CheckFieldsVisitor::kRawPtrToGCManagedWarning) {
         error = diag_raw_ptr_to_gc_managed_class_note_;
-      } else if (CheckFieldsVisitor::IsReferencePtrError(it->second)) {
-        error = diag_reference_ptr_to_gc_managed_class_note_;
       } else if (it->second == CheckFieldsVisitor::kRefPtrToGCManaged) {
         error = diag_ref_ptr_to_gc_managed_class_note_;
       } else if (it->second == CheckFieldsVisitor::kOwnPtrToGCManaged) {
@@ -2174,7 +2136,6 @@
   unsigned diag_field_requires_tracing_note_;
   unsigned diag_raw_ptr_to_gc_managed_class_note_;
   unsigned diag_ref_ptr_to_gc_managed_class_note_;
-  unsigned diag_reference_ptr_to_gc_managed_class_note_;
   unsigned diag_own_ptr_to_gc_managed_class_note_;
   unsigned diag_member_to_gc_unmanaged_class_note_;
   unsigned diag_stack_allocated_field_note_;