Supress the two noisiest warnings on linux standalone builds.

Code might someday be made clean for -Wmissing-field-initializers
and -Wsign-compare, but for now this produces too much noise to be
useful.

The -Wmissing-field-initializers warning is misguided in a high
percentage of cases, and actually leads to bad fixes.

R=brucedawson@chromium.org

Review URL: https://codereview.chromium.org/1094713002
diff --git a/build/standalone.gypi b/build/standalone.gypi
index 87fe344..186db6e 100644
--- a/build/standalone.gypi
+++ b/build/standalone.gypi
@@ -144,6 +144,10 @@
     'cflags': [
       '-Wall',
       '-W',
+      '-Wno-missing-field-initializers',
+      # Code might someday be made clean for -Wsign-compare, but for now
+      # this produces too much noise to be useful.
+      '-Wno-sign-compare',
       '-Wno-unused-parameter',
       '-pthread',
       '-fno-exceptions',