Revert "Turn on exceptions in test tools."

This reverts commit c667dff58dc4b16faf30c34e98a118c6a1c1f987.

Reason for revert: temporary while I fix Android, Google3.

Original change's description:
> Turn on exceptions in test tools.
> 
> This allows us to test things that, e.g., throw std::bad_alloc.
> 
> Change-Id: I6409159b89f1d93d403b1a1f40539cf2531a8b68
> Reviewed-on: https://skia-review.googlesource.com/34982
> Reviewed-by: Herb Derby <herb@google.com>
> Commit-Queue: Mike Klein <mtklein@chromium.org>

TBR=mtklein@chromium.org,herb@google.com

Change-Id: Iafdc34c5f70f99f7df3cd0bbad65eed0828453a1
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://skia-review.googlesource.com/35081
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>
diff --git a/gn/BUILD.gn b/gn/BUILD.gn
index 06cff4e..7be1617 100644
--- a/gn/BUILD.gn
+++ b/gn/BUILD.gn
@@ -258,16 +258,11 @@
 }
 
 config("no_exceptions") {
-  # Exceptions are disabled by default on Windows.  (Use :yes_exceptions to enable them.)
+  # Exceptions are disabled by default on Windows.  (Use /EHsc to enable them.)
   if (!is_win) {
     cflags_cc = [ "-fno-exceptions" ]
   }
 }
-config("yes_exceptions") {
-  if (is_win) {
-    cflags_cc = [ "/EHsc" ]
-  }
-}
 
 config("warnings") {
   cflags = []