rewrite_to_chrome_style: Make const decisions aware of const variables

tools/clang/rewrite_to_chrome_style/tests/template-original.cc

Index: tools/clang/rewrite_to_chrome_style/tests/template-original.cc
diff --git a/tools/clang/rewrite_to_chrome_style/tests/template-original.cc b/tools/clang/rewrite_to_chrome_style/tests/template-original.cc
index 679008290855c179aaf6b4f124228e471c789062..47aef5d85b6c7594312577e1d0aa73381c630986 100644
--- a/tools/clang/rewrite_to_chrome_style/tests/template-original.cc
+++ b/tools/clang/rewrite_to_chrome_style/tests/template-original.cc
@@ -63,6 +63,8 @@ void F() {
   const bool complexConst = number || (number + 1);
   // A complex statement with a non-const thing is not const.
   const bool complexNotConst = number || (g_globalNumber + 1);
+  // A const built from other consts is a const.
+  const bool constFromAConst = complexConst || number;
 }
 
 template <int number, typename... T>