Revert "Android: Enable C99 mode instead of C89 (default)."

webrtc/build/common.gypi

Index: webrtc/build/common.gypi
diff --git a/webrtc/build/common.gypi b/webrtc/build/common.gypi
index be1451d64326278c22af993957f660400d232a0f..5caa6cc10c84d8d0206ba667606b1ad3dd7dfbf1 100644
--- a/webrtc/build/common.gypi
+++ b/webrtc/build/common.gypi
@@ -373,18 +373,14 @@
          ],
          'conditions': [
            ['clang==0', {
+             # The Android NDK doesn't provide optimized versions of these
+             # functions. Ensure they are disabled for all compilers.
              'cflags': [
-               # The Android NDK doesn't provide optimized versions of these
-               # functions. Ensure they are disabled for all compilers.
                '-fno-builtin-cos',
                '-fno-builtin-sin',
                '-fno-builtin-cosf',
                '-fno-builtin-sinf',
              ],
-             'cflags_c': [
-               # Use C99 mode instead of C89 (default).
-               '-std=c99',
-             ]
            }],
          ],
       }],