Add local suppresion for -Wparentheses and enable everywhere on Windows.

The Cloud Print Windows service uses WTL, and one of the headers uses
an assignment inside a conditional (atlgdi.h), which triggers this clang
warning.

BUG=505302
TBR=scottbyer@chromium.org,vitalybuka@chromium.org

Review URL: https://codereview.chromium.org/1214113010

Cr-Original-Commit-Position: refs/heads/master@{#336964}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 700bce216cb9399ce306850ee66d3ce5a68c4cfa