Linux build: Use sysroot when calculating dependencies

tools/checklicenses/checklicenses.py

Index: tools/checklicenses/checklicenses.py
diff --git a/tools/checklicenses/checklicenses.py b/tools/checklicenses/checklicenses.py
index 3d27b0f2a06b1974ad54b3c107da3b2db1905fd9..48ccbeb6c5be933122cf2d3922f73a3fbf3bd0b9 100755
--- a/tools/checklicenses/checklicenses.py
+++ b/tools/checklicenses/checklicenses.py
@@ -234,6 +234,9 @@ PATH_SPECIFIC_WHITELISTED_LICENSES = {
     'third_party/devscripts': [
         'GPL (v2 or later)',
     ],
+    'third_party/dpkg-dev': [

[Lei Zhang, 2016/10/17 23:28:30]

I'm lgtm-ing this separately.

No need to stop the CQ, but it would be nice to add a bug number here so readers
can easily understand why this is here, and so you'll remember to remove it in
the near future.

[Tom (Use chromium acct), 2016/10/18 19:25:14]

Done.

+        'GPL (v2 or later)',
+    ],
     'third_party/catapult/firefighter/default/tracing/third_party/devscripts': [

[Lei Zhang, 2016/10/17 23:28:30]

Also, the 3 devscripts entries are grouped together. It would've been nice to
put it in a separate block.

[Tom (Use chromium acct), 2016/10/18 19:25:14]

Done.

         'GPL (v2 or later)',
     ],