Revert of [Telemetry] Make discover throw exceptions when it detects duplicate keys indexed by class name

Revert of [Telemetry] Make discover throw exceptions when it detects duplicate keys indexed by class name (patchset #2 id:20001 of https://codereview.chromium.org/2075743002/ )

Reason for revert:
Breaks all of the GPU tests on the Chromium waterfall: https://codereview.chromium.org/2136653002
https://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_rel_ng/builds/252404

Original issue's description:
> [Telemetry] Make discover throw exceptions when it detects duplicate keys indexed by class name
> 
> We don't  throw exceptions when there is duplicate keys indexed by 
> module name because telemetry_perf_unittest currently depends on this
> naming collision to reduce the number of benchmark it smokes test (bad!)
> 
> This CL also renames linux_based_platform_backend_unittest.TestBackend classes to 
> linux_based_platform_backend_unittest.TestLinuxBackend to
> avoid naming collision with posix_platform_backend_unittest.TestBackend (https://github.com/catapult-project/catapult/blob/a8a6fb7ea065c2df8ae129ad05ac80ba6ae7cc3a/telemetry/telemetry/internal/platform/posix_platform_backend_unittest.py#L13)
> 
> 
> Change announcement: https://groups.google.com/a/chromium.org/forum/#!topic/telemetry-announce/i6FlJJDFWQA)
> 
> Committed: https://chromium.googlesource.com/external/github.com/catapult-project/catapult/+/897866760cc7c37b766620f2589ad19026e775b1

TBR=kouhei@chromium.org,kbr@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Committed: https://chromium.googlesource.com/external/github.com/catapult-project/catapult/+/6cad5da3c39eca66c6dcd2db0b4cb1885fc00556

[nednguyen, 2016-07-09 01:22:10]

The CQ bit was checked by nednguyen@google.com

[nednguyen, 2016-07-09 01:22:10]

Created Revert of [Telemetry] Make discover throw exceptions when it detects
duplicate keys indexed by class name

[commit-bot: I haz the power, 2016-07-09 01:22:31]

Description was changed from

==========
Revert of [Telemetry] Make discover throw exceptions when it detects duplicate
keys indexed by class name (patchset #2 id:20001 of
https://codereview.chromium.org/2075743002/ )

Reason for revert:
Breaks all of the GPU tests on the Chromium waterfall:
https://codereview.chromium.org/2136653002
https://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_rel...

Original issue's description:
> [Telemetry] Make discover throw exceptions when it detects duplicate keys
indexed by class name
> 
> We don't  throw exceptions when there is duplicate keys indexed by 
> module name because telemetry_perf_unittest currently depends on this
> naming collision to reduce the number of benchmark it smokes test (bad!)
> 
> This CL also renames linux_based_platform_backend_unittest.TestBackend classes
to 
> linux_based_platform_backend_unittest.TestLinuxBackend to
> avoid naming collision with posix_platform_backend_unittest.TestBackend
(https://github.com/catapult-project/catapult/blob/a8a6fb7ea065c2df8ae129ad05a...)
> 
> 
> Change announcement:
https://groups.google.com/a/chromium.org/forum/#!topic/telemetry-announce/i6F...)
> 
> Committed:
https://chromium.googlesource.com/external/github.com/catapult-project/catapu...

TBR=kouhei@chromium.org,kbr@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
==========

to

==========
Revert of [Telemetry] Make discover throw exceptions when it detects duplicate
keys indexed by class name (patchset #2 id:20001 of
https://codereview.chromium.org/2075743002/ )

Reason for revert:
Breaks all of the GPU tests on the Chromium waterfall:
https://codereview.chromium.org/2136653002
https://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_rel...

Original issue's description:
> [Telemetry] Make discover throw exceptions when it detects duplicate keys
indexed by class name
> 
> We don't  throw exceptions when there is duplicate keys indexed by 
> module name because telemetry_perf_unittest currently depends on this
> naming collision to reduce the number of benchmark it smokes test (bad!)
> 
> This CL also renames linux_based_platform_backend_unittest.TestBackend classes
to 
> linux_based_platform_backend_unittest.TestLinuxBackend to
> avoid naming collision with posix_platform_backend_unittest.TestBackend
(https://github.com/catapult-project/catapult/blob/a8a6fb7ea065c2df8ae129ad05a...)
> 
> 
> Change announcement:
https://groups.google.com/a/chromium.org/forum/#!topic/telemetry-announce/i6F...)
> 
> Committed:
https://chromium.googlesource.com/external/github.com/catapult-project/catapu...

TBR=kouhei@chromium.org,kbr@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Committed:
https://chromium.googlesource.com/external/github.com/catapult-project/catapu...
==========

[nednguyen, 2016-07-12 18:54:06]

A revert of this CL (patchset #1 id:1) has been created in
https://codereview.chromium.org/2145693002/ by nednguyen@google.com.

The reason for reverting is: GPU tests are updated to avoid naming conflict in
https://codereview.chromium.org/2136773002/

BUG=chromium:627204.