Add HTMLMediaElement.preservesPitch

To adjust the playback rate of audio, we use two algorithms: resampling,
which shifts the audio's pitch, and WSOLA, which doesn't. At rates close
to 1.0, WSOLA can introduce undesirable artifacts for certain types of,
audio content, so we use resampling instead. However, this pitch shift
is noticeable can be less desirable than the WSOLA artifacts to some
users.

This CL implements the preservesPitch flag, which is already present in
Firefox and Safari. The flag allows web developers to choose between
pitch preserving and pitch shifting time stretch algorithms (resampling
and WSOLA in our case). This will allow users to chose the algorithm
that suites their needs at playback rates close to 1.0. It will also
allow users to use resampling at lower or higher playback rates, when
pitch shifting is desirable for aesthetic or performance purposes.

Bug: 1072067, 1096238
Change-Id: Ie0e7ff337da77c902a12259c30c33125104101ef
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2255179
Commit-Queue: Thomas Guilbert <tguilbert@chromium.org>
Reviewed-by: Chris Harrelson <chrishtr@chromium.org>
Reviewed-by: Dale Curtis <dalecurtis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#782141}

• media/base/audio_renderer.h[diff]
• media/base/mock_filters.h[diff]
• media/base/pipeline.h[diff]
• media/base/pipeline_impl.cc[diff]
• media/base/pipeline_impl.h[diff]
• media/base/pipeline_impl_unittest.cc[diff]
• media/base/renderer.cc[diff]
• media/base/renderer.h[diff]
• media/blink/webmediaplayer_impl.cc[diff]
• media/blink/webmediaplayer_impl.h[diff]
• media/filters/audio_renderer_algorithm.cc[diff]
• media/filters/audio_renderer_algorithm.h[diff]
• media/filters/audio_renderer_algorithm_unittest.cc[diff]
• media/filters/pipeline_controller.cc[diff]
• media/filters/pipeline_controller.h[diff]
• media/filters/pipeline_controller_unittest.cc[diff]
• media/fuchsia/audio/fuchsia_audio_renderer.cc[diff]
• media/fuchsia/audio/fuchsia_audio_renderer.h[diff]
• media/remoting/end2end_test_renderer.cc[diff]
• media/remoting/end2end_test_renderer.h[diff]
• media/renderers/audio_renderer_impl.cc[diff]
• media/renderers/audio_renderer_impl.h[diff]
• media/renderers/decrypting_renderer.cc[diff]
• media/renderers/decrypting_renderer.h[diff]
• media/renderers/renderer_impl.cc[diff]
• media/renderers/renderer_impl.h[diff]
• third_party/blink/public/platform/web_media_player.h[diff]
• third_party/blink/public/web/modules/mediastream/webmediaplayer_ms.h[diff]
• third_party/blink/renderer/core/html/media/html_media_element.cc[diff]
• third_party/blink/renderer/core/html/media/html_media_element.h[diff]
• third_party/blink/renderer/core/html/media/html_media_element.idl[diff]
• third_party/blink/renderer/modules/mediacapturefromelement/html_video_element_capturer_source_unittest.cc[diff]
• third_party/blink/renderer/modules/mediastream/webmediaplayer_ms.cc[diff]
• third_party/blink/renderer/platform/runtime_enabled_features.json5[diff]
• third_party/blink/renderer/platform/testing/empty_web_media_player.h[diff]
• third_party/blink/web_tests/webexposed/element-instance-property-listing-expected.txt[diff]
• third_party/blink/web_tests/webexposed/global-interface-listing-expected.txt[diff]