Setup for -Fast GCE bot.

I'd like a bot that has got optimization turned up to 11,
to let us test things that our Chrome-like bots normally can't.

(Not quite ready to commit this bot to -ffast-math yet.)

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1704473002

Review URL: https://codereview.chromium.org/1704473002
diff --git a/gyp/common_variables.gypi b/gyp/common_variables.gypi
index ba4d203..abbfaac 100644
--- a/gyp/common_variables.gypi
+++ b/gyp/common_variables.gypi
@@ -257,7 +257,7 @@
         '-O3',                   # Even for Debug builds.
         '-march=native',         # Use all features of and optimize for THIS machine.
         '-fomit-frame-pointer',  # Sometimes an extra register is nice, and cuts a push/pop.
-        '-ffast-math',           # Optimize float math even when it breaks IEEE compliance.
+        #'-ffast-math',           # Optimize float math even when it breaks IEEE compliance.
         #'-flto'                  # Enable link-time optimization.
     ],