[AudioService] Remove audio-sandbox command-line switch

Prior to this CL, a command-line switch was set in the browser process
and copied to the utility process to enable the audio sandbox.
This was not ideal since it resulted in the browser command line being
altered, which is visible, for example, in chrome://version for
platforms that have the sandbox enabled by default.

This CL replaces the switch with a method in ContentBrowserClient which
indicates if the audio service should be sandboxed or not.
The result of this method is used to set the type of sandbox to be used
(kAudio or kNoSandbox).


Bug: 1057969
Change-Id: I5fe214795daf6af67c03984c8c59516641fa19c4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2302193
Reviewed-by: Scott Violet <sky@chromium.org>
Reviewed-by: Will Harris <wfh@chromium.org>
Commit-Queue: Guido Urdaneta <guidou@chromium.org>
Cr-Commit-Position: refs/heads/master@{#790723}

• chrome/browser/BUILD.gn[diff]
• chrome/browser/chrome_content_browser_client.cc[diff]
• chrome/browser/chrome_content_browser_client.h[diff]
• chrome/browser/extensions/api/tab_capture/tab_capture_performance_test_base.cc[diff]
• chrome/browser/media/audio_service_util.cc[Added - diff]
• chrome/browser/media/audio_service_util.h[Added - diff]
• chrome/browser/media/webrtc/webrtc_text_log_handler.cc[diff]
• chrome/browser/policy/policy_browsertest.cc[diff]
• content/browser/media/media_internals.cc[diff]
• content/browser/service_sandbox_type.h[diff]
• content/browser/utility_process_host.cc[diff]
• content/public/browser/content_browser_client.cc[diff]
• content/public/browser/content_browser_client.h[diff]
• content/public/common/content_features.cc[diff]
• content/public/common/content_features.h[diff]
• content/utility/services.cc[diff]
• sandbox/policy/features.cc[diff]
• sandbox/policy/features.h[diff]
• sandbox/policy/sandbox_type.cc[diff]
• sandbox/policy/sandbox_type.h[diff]
• sandbox/policy/switches.cc[diff]
• sandbox/policy/switches.h[diff]