MSE-in-Workers: Drop unused attachment interface methods

This change drops two unnecessary methods from the MediaSourceAttachment
interface:

1) As of r680382, HTMLMediaElement no longer needs the
   Oilpan/GarbageCollected TimeRanges version of Buffered() from the
   MediaSource API. Rather, it constructs its own TimeRanges when needed
   by consulting the underlying WebTimeRanges produced by
   BufferedInternal.

2) Also, when creating the core attachment interface and removing the
   core MediaSource interface, the duration() method was unnecessarily
   included in the attachment. Even before this MSE-in-Workers feature
   work, duration notification updates (where the media element is
   notified that the underlying MSE resource's duration has changed) did
   not involve this method.

This change also includes some minor clean-ups of the
modules/mediasource attachment includes.

BUG=878133

Change-Id: I125f9db2bf1383c2eafb312225e3f843371a744f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2402169
Commit-Queue: Matthew Wolenetz <wolenetz@chromium.org>
Reviewed-by: Philip Jägenstedt <foolip@chromium.org>
Cr-Commit-Position: refs/heads/master@{#807289}

third_party/blink/renderer/core/html/media/media_source_attachment.h

@@ -19,7 +19,6 @@ namespace blink {
 
 class HTMLMediaElement;
 class MediaSourceRegistry;
-class TimeRanges;
 class TrackBase;
 class WebMediaSource;
 
@@ -95,13 +94,12 @@ class CORE_EXPORT MediaSourceAttachment
       std::unique_ptr<WebMediaSource>) = 0;
 
   virtual void Close(MediaSourceTracer* tracer) = 0;
-  virtual double duration(MediaSourceTracer* tracer) const = 0;
 
   // 'Internal' in these methods doesn't mean private, it means that they are
   // internal to chromium and are not exposed to JavaScript.
   virtual WebTimeRanges BufferedInternal(MediaSourceTracer* tracer) const = 0;
   virtual WebTimeRanges SeekableInternal(MediaSourceTracer* tracer) const = 0;
-  virtual TimeRanges* Buffered(MediaSourceTracer* tracer) const = 0;
+
   virtual void OnTrackChanged(MediaSourceTracer* tracer, TrackBase*) = 0;
 
   // Provide state updates to the MediaSource that are necessary for its

third_party/blink/renderer/modules/mediasource/media_source_attachment_supplement.h

@@ -5,8 +5,6 @@
 #ifndef THIRD_PARTY_BLINK_RENDERER_MODULES_MEDIASOURCE_MEDIA_SOURCE_ATTACHMENT_SUPPLEMENT_H_
 #define THIRD_PARTY_BLINK_RENDERER_MODULES_MEDIASOURCE_MEDIA_SOURCE_ATTACHMENT_SUPPLEMENT_H_
 
-#include <memory>
-#include "third_party/blink/public/platform/web_time_range.h"
 #include "third_party/blink/renderer/core/html/media/media_source_attachment.h"
 #include "third_party/blink/renderer/core/html/media/media_source_tracer.h"
 #include "third_party/blink/renderer/modules/mediasource/media_source.h"

third_party/blink/renderer/modules/mediasource/same_thread_media_source_attachment.cc

@@ -123,13 +123,6 @@ void SameThreadMediaSourceAttachment::Close(MediaSourceTracer* tracer) {
   GetMediaSource(tracer)->Close();
 }
 
-double SameThreadMediaSourceAttachment::duration(
-    MediaSourceTracer* tracer) const {
-  VerifyCalledWhileContextsAliveForDebugging();
-
-  return GetMediaSource(tracer)->duration();
-}
-
 WebTimeRanges SameThreadMediaSourceAttachment::BufferedInternal(
     MediaSourceTracer* tracer) const {
   VerifyCalledWhileContextsAliveForDebugging();
@@ -144,13 +137,6 @@ WebTimeRanges SameThreadMediaSourceAttachment::SeekableInternal(
   return GetMediaSource(tracer)->SeekableInternal();
 }
 
-TimeRanges* SameThreadMediaSourceAttachment::Buffered(
-    MediaSourceTracer* tracer) const {
-  VerifyCalledWhileContextsAliveForDebugging();
-
-  return GetMediaSource(tracer)->Buffered();
-}
-
 void SameThreadMediaSourceAttachment::OnTrackChanged(MediaSourceTracer* tracer,
                                                      TrackBase* track) {
   // In this same thread implementation, the MSE side of the attachment can loop

third_party/blink/renderer/modules/mediasource/same_thread_media_source_attachment.h

@@ -5,6 +5,9 @@
 #ifndef THIRD_PARTY_BLINK_RENDERER_MODULES_MEDIASOURCE_SAME_THREAD_MEDIA_SOURCE_ATTACHMENT_H_
 #define THIRD_PARTY_BLINK_RENDERER_MODULES_MEDIASOURCE_SAME_THREAD_MEDIA_SOURCE_ATTACHMENT_H_
 
+#include <memory>
+
+#include "third_party/blink/public/platform/web_time_range.h"
 #include "third_party/blink/renderer/modules/mediasource/media_source.h"
 #include "third_party/blink/renderer/modules/mediasource/media_source_attachment_supplement.h"
 
@@ -32,10 +35,8 @@ class SameThreadMediaSourceAttachment final
       std::unique_ptr<WebMediaSource>) override;
 
   void Close(MediaSourceTracer* tracer) override;
-  double duration(MediaSourceTracer* tracer) const override;
   WebTimeRanges BufferedInternal(MediaSourceTracer* tracer) const override;
   WebTimeRanges SeekableInternal(MediaSourceTracer* tracer) const override;
-  TimeRanges* Buffered(MediaSourceTracer* tracer) const override;
   void OnTrackChanged(MediaSourceTracer* tracer, TrackBase*) override;
 
   void OnElementTimeUpdate(double time) final;