Make net_unittests_run work with component=shared_library.

third_party/nss.isolate

+# Copyright 2014 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+#
+# Note: this file should live in third_party/nss but two problems get in the
+# way:
+# - .isolate files do not support conditional includes. This works in gyp by
+#   using the 'dependencies': [ 'path/to/file.gyp:project' ] which dynamically
+#   loads project files.
+# - third_party/nss is conditionally checked out. It is not checked out on
+#   linux.

[Ryan Sleevi, 2014/01/27 21:27:38]

Isn't this a case for where we do what libjingle/webrtc is doing?

eg:

third_party/nss = unconditionally checked out
third_party/nss/nss.isolate
third_party/nss/src = conditionally checked out bits (eg: On mac/win/iOS)

That requires a infrastructure coordination, so should be done in a separate
bug, unless you expect to see a bunch of .isolate's in this folder. If so,
should we have third_party/isolate to contain these files? IDK, sticking them at
top-level seems as weird as sticking nss.gyp here

[M-A Ruel, 2014/01/27 21:34:48]

Go on your linux machine and see what is there. third_party/nss is empty. Or see
the DEPS file.

Doing this *is* bad but sadly there's no third_party/nss/src layout.

[Ryan Sleevi, 2014/01/27 21:45:30]

I'm aware of what we have, I was trying to say whether this should be a TODO()
[or pre-requisite]  to make NSS support this.

The answer to this is somewhat contingent on how you plan to handle other
third-party libraries - particularly those that may be conditionally checked
out, since I don't think this will be your only case, and sticking them all in
src/third_party seems... gross :)

[M-A Ruel, 2014/01/28 21:41:26]

I think it's going to be gross for a while. It's a trade off here, I'm focusing
on getting this working at all in a way that doesn't interfere too much with
others. I built unit_tests in component builds and the next CL is going to be
quite fun. That said, not polluting third_part is something I care about so I'll
like about alternatives. One option I am playing with is "optional includes" or
"includes inside condition". I'm still undecided about the route I'm going to
take, it'll depend how bad things are going to be. Once I made enough progress,
I'll implement the correct fix and will go back moving the .isolate files
accordingly.

+{
+  'conditions': [
+    ['OS=="mac" and component=="shared_library"', {
+      'variables': {
+        'isolate_dependency_tracked': [
+          '<(PRODUCT_DIR)/libcrnspr.dylib',
+          '<(PRODUCT_DIR)/libcrnss.dylib',
+        ],
+      },
+    }],
+    ['OS=="win" and component=="shared_library"', {
+      'variables': {
+        'isolate_dependency_tracked': [
+          '<(PRODUCT_DIR)/crnspr.dll',
+          '<(PRODUCT_DIR)/crnss.dll',
+        ],
+      },
+    }],
+  ],
+}