The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/15e0e74f4dbd7616a722702eedd6620b70f50290

commit 15e0e74f4dbd7616a722702eedd6620b70f50290
Author: brettw <brettw@chromium.org>
Date: Tue Jul 26 18:00:24 2016

Allow GN toolchains to specify runtime deps outputs.

Previously the file considered for the runtime deps computation for linked
targets was just the first output, or, for shared libraries, the
runtime_link_output.

This patch changes that to a list of files for all linker tools. This will
allow us, for example, to be able to automatically bundle symbol files
generated by the build (but not .lib files in the case of shared libraries) to
the swarming bots for testing.

The tool class setters now take objects by copies and move them to avoid extra
copies in many cases. Add a defined_from member to the Tool class.

BUG= 631242 

Review-Url: https://codereview.chromium.org/2178173002
Cr-Commit-Position: refs/heads/master@{#407852}

[modify] https://crrev.com/15e0e74f4dbd7616a722702eedd6620b70f50290/build/toolchain/win/BUILD.gn
[modify] https://crrev.com/15e0e74f4dbd7616a722702eedd6620b70f50290/tools/gn/BUILD.gn
[modify] https://crrev.com/15e0e74f4dbd7616a722702eedd6620b70f50290/tools/gn/function_toolchain.cc
[add] https://crrev.com/15e0e74f4dbd7616a722702eedd6620b70f50290/tools/gn/function_toolchain_unittest.cc
[modify] https://crrev.com/15e0e74f4dbd7616a722702eedd6620b70f50290/tools/gn/gn.gyp
[modify] https://crrev.com/15e0e74f4dbd7616a722702eedd6620b70f50290/tools/gn/runtime_deps.cc
[modify] https://crrev.com/15e0e74f4dbd7616a722702eedd6620b70f50290/tools/gn/target.cc
[modify] https://crrev.com/15e0e74f4dbd7616a722702eedd6620b70f50290/tools/gn/target.h
[modify] https://crrev.com/15e0e74f4dbd7616a722702eedd6620b70f50290/tools/gn/target_unittest.cc
[modify] https://crrev.com/15e0e74f4dbd7616a722702eedd6620b70f50290/tools/gn/tool.h