Roll clang to 4db5854

AKA roll clang 310694:312679

Fix virtual dtor warning in xfa/fde/cfde_texteditengine.h

Bug: pdfium:896
Change-Id: Ib5fb9433b2c138ca46ccb281b8c0a852daeb623e
Reviewed-on: https://pdfium-review.googlesource.com/13850
Commit-Queue: Tom Sepez <tsepez@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>
diff --git a/DEPS b/DEPS
index 212ba6e..b06166c 100644
--- a/DEPS
+++ b/DEPS
@@ -8,7 +8,7 @@
   'build_revision': '34f9a2ba2ac2bdc70dbdf11644753d81d7ebfeda',
   'buildtools_revision': 'f90f6a5af3e8cf843395bfe6243cf606f71b5344',
   'catapult_revision': '0cf3924bab2c2f66a412edda35f6e3572bd57623',
-  'clang_revision': 'a1420b85586c1fa3eaf68808bbb095334d2d271d',
+  'clang_revision': '4db585405687222660050d58eb12784fe0852884',
   'cygwin_revision': 'c89e446b273697fadf3a10ff1007a97c0b7de6df',
   'freetype_revision': '7e50824288fac5a36c2938fdb3e1c949ea53f982',
   'gmock_revision': '29763965ab52f24565299976b936d1265cb6a271',
diff --git a/xfa/fde/cfde_texteditengine.h b/xfa/fde/cfde_texteditengine.h
index 63b3b53..aa8a243 100644
--- a/xfa/fde/cfde_texteditengine.h
+++ b/xfa/fde/cfde_texteditengine.h
@@ -63,8 +63,8 @@
 
   class Delegate {
    public:
+    virtual ~Delegate() = default;
     virtual void NotifyTextFull() = 0;
-
     virtual void OnCaretChanged() = 0;
     virtual void OnTextChanged(const CFX_WideString& prevText) = 0;
     virtual void OnSelChanged() = 0;