Do not build breakpad tool on target when cross-compiling for iOS

Do not build breakpad tool on target when cross-compiling for iOS

The "microdump_stackwalk", "minidump_stackwalk", and "minidump_dump" tools
are not expected to be run on the device, so only build them for "host"
toolset not "target" when targetting iOS.

When building for other targets build the tools both for "host" and "target"
to fix compilation of ChromeOS build in `cros chrome-sdk` shells.

BUG=459035
TBR=mark

Committed: https://chromium.googlesource.com/chromium/src/+/8196d17c34a51b5b00df2e43bcd8f3ad8a74b5d5

[sdefresne, 2015-02-18 19:55:52]

sdefresne@chromium.org changed reviewers:
+ mark@chromium.org, smckay@chromium.org

[sdefresne, 2015-02-18 19:55:53]

Mark: can you take a look? I hear this is blocking cros guys.

[sdefresne, 2015-02-18 20:03:48]

TBR-ing since this is resolving a tree closure for ChromeOS.

[commit-bot: I haz the power, 2015-02-18 20:06:49]

Patchset 1 (id:??) landed as
https://crrev.com/8196d17c34a51b5b00df2e43bcd8f3ad8a74b5d5
Cr-Commit-Position: refs/heads/master@{#316879}

[sdefresne, 2015-02-18 20:07:00]

Committed patchset #1 (id:1) manually as
8196d17c34a51b5b00df2e43bcd8f3ad8a74b5d5 (presubmit successful).

[Steve McKay, 2015-02-18 20:11:22]

LGTM. Tested locally and it fixed my Chrome OS cros shell build.

[Mark Mentovai, 2015-02-18 21:05:06]

LGTM