Revert of [tools/perf] Remove default values of benchmark_dirs and top_level_dir in chromium_config module (patchset #2 id:20001 of https://codereview.chromium.org/2821663002/ )

Reason for revert:
Suspected to be breaking various tests, e.g.:

https://build.chromium.org/p/chromium.gpu/builders/Mac%20Release%20%28Intel%29/builds/62430

https://build.chromium.org/p/chromium.gpu/builders/Linux%20Release%20%28NVIDIA%29/builds/100927

https://build.chromium.org/p/chromium.mac/builders/Mac10.9%20Tests/builds/39799

The logs show a python failure similar to

Traceback (most recent call last): File "../../content/test/gpu/run_unittests.py", line 15, in <module> path_util.SetupTelemetryPaths() File "/b/swarm_slave/w/ir/content/test/gpu/gpu_tests/path_util.py", line 31, in SetupTelemetryPaths from chrome_telemetry_build import chromium_config File "/b/swarm_slave/w/ir/tools/perf/chrome_telemetry_build/chromium_config.py", line 7, in <module> from core import path_util ImportError: No module named core

Original issue's description:
> [tools/perf] Remove default values of benchmark_dirs and top_level_dir in chromium_config module
>
> Part of this CL also moves GetChromiumSrcDir & GetTelemetryDir methods to
> tools.perf.core.path_util module
>
> Motivation: to move experiemental benchmarks to a separate folder & still
> make run_benchmarks be able to detect them,  I will need to modify
> run_benchmarks to also include experiemental benchmark folder in
> |benchmark_dirs| parameter. Upon doing that, I find that there is no need
> to set the default the value of benchmark_dirs & top_level_dir.
>
> BUG=709063
> TBR=perezju@chromium.org
>
> Review-Url: https://codereview.chromium.org/2821663002
> Cr-Commit-Position: refs/heads/master@{#465016}
> Committed: https://chromium.googlesource.com/chromium/src/+/09cd8622560496d63dd16d0b10a7c515dbc5c3ff

TBR=martiniss@chromium.org,ashleymarie@chromium.org,perezju@chromium.org,nednguyen@google.com
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=709063

Review-Url: https://codereview.chromium.org/2823063003
Cr-Commit-Position: refs/heads/master@{#465038}
4 files changed