olka@ could you please look into this.please feel free to re-assigned back if needed. thanks in advance !

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/64b9793077e8daf693a06eab4b98dc5a6374630d

commit 64b9793077e8daf693a06eab4b98dc5a6374630d
Author: olka <olka@chromium.org>
Date: Mon Oct 31 16:13:58 2016

Checking RendererThreadImpl for null when creating media player.

Also adding CHECKs for it not being nullptr in AudioDeviceFactory.
RendererThreadImpl lives in TLS, and a call to
lazy_tls.Pointer()->Get()::GetAudioRendererMixerManager()
(
https://cs.chromium.org/chromium/src/content/renderer/media/audio_device_factory.cc?dr=CSs&q=AudioDeviceFa&sq=package:chromium&l=76
https://cs.chromium.org/chromium/src/content/renderer/render_thread_impl.cc?q=RenderThreadImpl::current&sq=package:chromium&dr=CSs&l=1575)
end up accessing |audio_renderer_mixer_manager_| of nullptr.

BUG= 657167 
TESTING=running failed clusterfuzz test locally: test passes after the fix.

Review-Url: https://codereview.chromium.org/2460303003
Cr-Commit-Position: refs/heads/master@{#428728}

[modify] https://crrev.com/64b9793077e8daf693a06eab4b98dc5a6374630d/content/renderer/media/audio_device_factory.cc
[modify] https://crrev.com/64b9793077e8daf693a06eab4b98dc5a6374630d/content/renderer/render_frame_impl.cc

ClusterFuzz has detected this issue as fixed in range 428710:428740.

Detailed report: https://cluster-fuzz.appspot.com/testcase?key=4609103047688192

Fuzzer: libfuzzer_renderer_tree_fuzzer
Job Type: libfuzzer_chrome_asan
Platform Id: linux

Crash Type: UNKNOWN READ
Crash Address: 0x000000000478
Crash State:
  content::RenderThreadImpl::GetAudioRendererMixerManager
  content::NewMixableSink
  content::AudioDeviceFactory::NewSwitchableAudioRendererSink
  
Regressed: https://cluster-fuzz.appspot.com/revisions?job=libfuzzer_chrome_asan&range=423381:423433
Fixed: https://cluster-fuzz.appspot.com/revisions?job=libfuzzer_chrome_asan&range=428710:428740

Minimized Testcase (0.16 Kb): https://cluster-fuzz.appspot.com/download/AMIfv978o_Hq-jMfps22aSg0XZCd6kfT1lpPcOe3BEZDtWUJcxASgf6Dw6u5e6nqlKP0BIUnSfddNbdz0u4XK1BhrCU8oJNumnh5foY-XlK022VDTCS_yH47V9RmagTttl27hAzb1H_-u7g69x1W7jPMxjF-tBoZMQ?testcase_id=4609103047688192

See https://chromium.googlesource.com/chromium/src/+/master/testing/libfuzzer/reproducing.md for more information.

If you suspect that the result above is incorrect, try re-doing that job on the test case report page.

Removing EditIssue view restrictions from ClusterFuzz filed bugs. If you believe that this issue should still be restricted, please reapply the label.

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