Fix mac remoting GN build failures.

Fix mac remoting GN build failures.

In the official GN builds on the mac, there were two issues w/ the GN
build. The first was that one of the targets was missing a dependency
and links could fail, and the second was that building the installer
would inadvertently delete a generated file, leading the build to always
be dirty.

R=rsesek@chromium.org, nicholss@chromium.org, brettw@chromium.org
BUG=623685
Committed: https://crrev.com/c724e93ce54205fa9dc57f0cd00429a40308c178
Cr-Commit-Position: refs/heads/master@{#404941}

[Dirk Pranke, 2016-07-12 20:57:39]

https://codereview.chromium.org/2142233002/diff/1/remoting/host/BUILD.gn
File remoting/host/BUILD.gn (right):

https://codereview.chromium.org/2142233002/diff/1/remoting/host/BUILD.gn#newc...
remoting/host/BUILD.gn:1239: rebase_path("$root_gen_dir/remoting_installation",
root_build_dir),
The GYP build actually uses SHARED_INTERMEDIATE_DIR/installation, but I felt
that directory name was dangerously not unique enough.

https://codereview.chromium.org/2142233002/diff/1/remoting/host/BUILD.gn#newc...
remoting/host/BUILD.gn:1317: root_build_dir),
This uses target_gen_dir instead of root_gen_dir, because the dir doesn't need
to be shared between targets, but I re-use "remoting_installation" to be more
consistent w/ the win version. in the GYP build, the mac uses a different name,
but I don't see an obvious reason for it.

[Dirk Pranke, 2016-07-12 20:58:33]

The CQ bit was checked by dpranke@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-07-12 20:59:57]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[nicholss, 2016-07-12 21:10:45]

lgtm

[brettw, 2016-07-12 21:16:13]

lgtm

[Robert Sesek, 2016-07-12 21:16:36]

lgtm. Thanks, I was about to start looking at this :)

[commit-bot: I haz the power, 2016-07-13 00:25:58]

The CQ bit was unchecked by commit-bot@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-07-13 00:26:02]

Dry run: Try jobs failed on following builders:
  linux_chromium_asan_rel_ng on master.tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[Dirk Pranke, 2016-07-13 00:28:35]

The CQ bit was checked by dpranke@chromium.org

[Dirk Pranke, 2016-07-13 00:28:36]

The CQ bit was unchecked by dpranke@chromium.org

[Dirk Pranke, 2016-07-13 00:28:37]

The CQ bit was checked by dpranke@chromium.org

[commit-bot: I haz the power, 2016-07-13 00:35:07]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-07-13 03:06:28]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-07-13 03:08:57]

Description was changed from

==========
Fix mac remoting GN build failures.

In the official GN builds on the mac, there were two issues w/ the GN
build. The first was that one of the targets was missing a dependency
and links could fail, and the second was that building the installer
would inadvertently delete a generated file, leading the build to always
be dirty.

R=rsesek@chromium.org, nicholss@chromium.org, brettw@chromium.org
BUG=623685
==========

to

==========
Fix mac remoting GN build failures.

In the official GN builds on the mac, there were two issues w/ the GN
build. The first was that one of the targets was missing a dependency
and links could fail, and the second was that building the installer
would inadvertently delete a generated file, leading the build to always
be dirty.

R=rsesek@chromium.org, nicholss@chromium.org, brettw@chromium.org
BUG=623685

Committed: https://crrev.com/c724e93ce54205fa9dc57f0cd00429a40308c178
Cr-Commit-Position: refs/heads/master@{#404941}
==========

[commit-bot: I haz the power, 2016-07-13 03:08:59]

Patchset 1 (id:??) landed as
https://crrev.com/c724e93ce54205fa9dc57f0cd00429a40308c178
Cr-Commit-Position: refs/heads/master@{#404941}