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/gammatext.cpp b/gm/gammatext.cpp
index a2b6de5..4949494 100644
--- a/gm/gammatext.cpp
+++ b/gm/gammatext.cpp
@@ -89,7 +89,7 @@
     }
 
 private:
-    typedef skiagm::GM INHERITED;
+    using INHERITED = skiagm::GM;
 };
 
 DEF_GM( return new GammaTextGM; )
@@ -156,7 +156,7 @@
     }
 
 private:
-    typedef skiagm::GM INHERITED;
+    using INHERITED = skiagm::GM;
 };
 
 DEF_GM( return new GammaShaderTextGM; )