Disable exceptions on Windows in all builds (take 4)

Disable exceptions on Windows in all builds (take 4)

They were previously enabled in shared_library builds for historical reasons.

Turning them off makes things nice and consistent across all build types,
and helps the Windows Clang build, which currently doesn't support exceptions.

Previous attemps failed due to:

- mojo_public_environment_unittests unreachable code warning in
  DrMemory shared_library Release builds (crbug.com/397465)
  Fixed in Chromium r285674.

- chrome_elf_unittests on x64 (crbug.com/396244)
  Fixed in Chromium r285377.

- blink_platform_unittests:DateTimeFormatTest.CommonPattern et al.
  Fixed in Blink r176189

BUG=82385
TBR=thakis

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=285676

[hans, 2014-07-25 21:02:46]

Committed patchset #1 manually as r285676 (presubmit successful).

[Nico, 2014-07-25 21:07:03]

lgtm

[hans, 2014-07-25 21:18:43]

On 2014/07/25 21:07:03, Nico (away) wrote:
> lgtm

(I have no idea why it didn't use my @chromium.org address in the commit :/ )