Replace 'typedef xxxxx INHERITED' with 'using INHERITED = xxxx;'.

Mechanically updated via Xcode "Replace Regular Expression":

  typedef (.*) INHERITED;
    -->
  using INHERITED = $1;

The ClangTidy approach generated an even larger CL which would have
required a significant amount of hand-tweaking to be usable.

Change-Id: I671dc9d9efdf6d60151325c8d4d13fad7e10a15b
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/314999
Commit-Queue: Mike Klein <mtklein@google.com>
Reviewed-by: Mike Klein <mtklein@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
diff --git a/gm/convexpolyclip.cpp b/gm/convexpolyclip.cpp
index 8d53b50..3e78054 100644
--- a/gm/convexpolyclip.cpp
+++ b/gm/convexpolyclip.cpp
@@ -304,7 +304,7 @@
     ClipList         fClips;
     SkBitmap         fBmp;
 
-    typedef GM INHERITED;
+    using INHERITED = GM;
 };
 
 DEF_GM(return new ConvexPolyClip;)