Move gtest/gmock BUILD.gn files to main tree.

testing/gtest/BUILD.gn

Index: testing/gtest/BUILD.gn
diff --git a/tools/gn/secondary/testing/gtest/BUILD.gn b/testing/gtest/BUILD.gn
similarity index 96%
rename from tools/gn/secondary/testing/gtest/BUILD.gn
rename to testing/gtest/BUILD.gn
index b77d178c14563def5271ae0b8f60f0a28f7639ce..4335ac366f8ffad971f59b3849f7e4a9d45a1366 100644
--- a/tools/gn/secondary/testing/gtest/BUILD.gn
+++ b/testing/gtest/BUILD.gn
@@ -14,10 +14,6 @@ config("gtest_config") {
   # Gtest headers need to be able to find themselves.
   include_dirs = [ "include" ]
 
-  if (is_win) {
-    cflags = [ "/wd4800" ]  # Unused variable warning.
-  }
-
   if (is_posix) {
     defines += [
       # gtest isn't able to figure out when RTTI is disabled for gcc
@@ -78,6 +74,11 @@ static_library("gtest") {
   include_dirs = [ "." ]
 
   all_dependent_configs = [ ":gtest_config" ]
+  if (is_win) {
+    all_dependent_configs += [
+      "//build/config/win:disable_unused_variable_warning",
+    ]
+  }
 
   configs -= [ "//build/config/compiler:chromium_code" ]
   configs += [ "//build/config/compiler:no_chromium_code" ]