Revert "[Media Router] Better sink availability tracking"

This reverts commit 52dda118.

Reason for revert: Breaks Linux x64 build:
https://logs.chromium.org/v/?s=chromium%2Fbb%2Fchromium%2FLinux_x64%2F54249%2F%2B%2Frecipes%2Fsteps%2Fcompile%2F0%2Fstdout

Original change's description:
> [Media Router] Better sink availability tracking
> 
> - When sink availability changes for an MRP, start/stop observing sinks only for that MRP
> - Make WiredDisplayMRP report sink availability updates
> 
> Bug: 789277,777650
> Change-Id: I3d1a087ca39a4830403d6d2f0f00bf1411388f33
> Reviewed-on: https://chromium-review.googlesource.com/794106
> Reviewed-by: Derek Cheng <imcheng@chromium.org>
> Commit-Queue: Takumi Fujimoto <takumif@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#521550}

TBR=imcheng@chromium.org,takumif@chromium.org

Change-Id: Id4d13f0b2097ccfe398b05ce239d21c5d3c2b626
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 789277, 777650
Reviewed-on: https://chromium-review.googlesource.com/807588Reviewed-by: Thomas Anderson <thomasanderson@chromium.org>
Commit-Queue: Thomas Anderson <thomasanderson@chromium.org>
Cr-Commit-Position: refs/heads/master@{#521561}

chrome/browser/media/router/mojo/media_router_mojo_impl.cc

@@ -538,14 +538,6 @@ bool MediaRouterMojoImpl::ProviderSinkAvailability::SetAvailabilityForProvider(
   }
 }
 
-bool MediaRouterMojoImpl::ProviderSinkAvailability::IsAvailableForProvider(
-    mojom::MediaRouteProvider::Id provider_id) const {
-  const auto& it = availabilities_.find(provider_id);
-  return it == availabilities_.end()
-             ? false
-             : it->second != SinkAvailability::UNAVAILABLE;
-}
-
 bool MediaRouterMojoImpl::ProviderSinkAvailability::IsAvailable() const {
   return overall_availability_ != SinkAvailability::UNAVAILABLE;
 }
@@ -586,11 +578,9 @@ bool MediaRouterMojoImpl::RegisterMediaSinksObserver(
 
   // If sink availability is UNAVAILABLE or the query isn't new, then there is
   // no need to call MRPs.
-  if (is_new_query) {
-    for (const auto& provider : media_route_providers_) {
-      if (sink_availability_.IsAvailableForProvider(provider.first))
-        provider.second->StartObservingMediaSinks(source_id);
-    }
+  if (availability_.IsAvailable() && is_new_query) {
+    for (const auto& provider : media_route_providers_)
+      provider.second->StartObservingMediaSinks(source_id);
   }
   return true;
 }
@@ -601,8 +591,9 @@ void MediaRouterMojoImpl::UnregisterMediaSinksObserver(
 
   const MediaSource::Id& source_id = observer->source().id();
   auto it = sinks_queries_.find(source_id);
-  if (it == sinks_queries_.end() || !it->second->HasObserver(observer))
+  if (it == sinks_queries_.end() || !it->second->HasObserver(observer)) {
     return;
+  }
 
   // If we are removing the final observer for the source, then stop
   // observing sinks for it.
@@ -612,8 +603,8 @@ void MediaRouterMojoImpl::UnregisterMediaSinksObserver(
   if (!it->second->HasObservers()) {
     // Only ask MRPs to stop observing media sinks if there are sinks available.
     // Otherwise, the MRPs would have discarded the queries already.
-    for (const auto& provider : media_route_providers_) {
-      if (sink_availability_.IsAvailableForProvider(provider.first))
+    if (availability_.IsAvailable()) {
+      for (const auto& provider : media_route_providers_)
         provider.second->StopObservingMediaSinks(source_id);
     }
     sinks_queries_.erase(source_id);
@@ -762,15 +753,16 @@ void MediaRouterMojoImpl::OnRouteMessagesReceived(
 void MediaRouterMojoImpl::OnSinkAvailabilityUpdated(
     MediaRouteProviderId provider_id,
     SinkAvailability availability) {
-  if (!sink_availability_.SetAvailabilityForProvider(provider_id, availability))
+  if (!availability_.SetAvailabilityForProvider(provider_id, availability))
     return;
 
-  if (availability != SinkAvailability::UNAVAILABLE) {
-    // Sinks are now available. Tell the MRP to start all sink queries again.
-    auto& provider = media_route_providers_[provider_id];
-    for (const auto& source_and_query : sinks_queries_)
-      provider->StartObservingMediaSinks(source_and_query.first);
-  } else if (!sink_availability_.IsAvailable()) {
+  if (availability_.IsAvailable()) {
+    // Sinks are now available. Tell MRPs to start all sink queries again.
+    for (const auto& source_and_query : sinks_queries_) {
+      for (const auto& provider : media_route_providers_)
+        provider.second->StartObservingMediaSinks(source_and_query.first);
+    }
+  } else {
     // Sinks are no longer available. MRPs have already removed all sink
     // queries.
     for (auto& source_and_query : sinks_queries_)
@@ -815,7 +807,7 @@ void MediaRouterMojoImpl::SyncStateToMediaRouteProvider(
     MediaRouteProviderId provider_id) {
   const auto& provider = media_route_providers_[provider_id];
   // Sink queries.
-  if (sink_availability_.IsAvailableForProvider(provider_id)) {
+  if (availability_.IsAvailable()) {
     for (const auto& it : sinks_queries_)
       provider->StartObservingMediaSinks(it.first);
   }

chrome/browser/media/router/mojo/media_router_mojo_impl.h

@@ -296,10 +296,6 @@ class MediaRouterMojoImpl : public MediaRouterBase,
     bool SetAvailabilityForProvider(MediaRouteProviderId provider_id,
                                     SinkAvailability availability);
 
-    // Returns true if the availability for the provider is not UNAVAILABLE.
-    bool IsAvailableForProvider(
-        mojom::MediaRouteProvider::Id provider_id) const;
-
     // Returns true if there is a provider whose sink availability isn't
     // UNAVAILABLE.
     bool IsAvailable() const;
@@ -411,7 +407,7 @@ class MediaRouterMojoImpl : public MediaRouterBase,
   std::string instance_id_;
 
   // The last reported sink availability from the media route providers.
-  ProviderSinkAvailability sink_availability_;
+  ProviderSinkAvailability availability_;
 
   // Bindings for Mojo pointers to |this| held by media route providers.
   mojo::BindingSet<mojom::MediaRouter> bindings_;

chrome/browser/media/router/mojo/wired_display_media_route_provider.cc

@@ -68,7 +68,6 @@ WiredDisplayMediaRouteProvider::WiredDisplayMediaRouteProvider(
     : binding_(this, std::move(request)),
       media_router_(std::move(media_router)) {
   display::Screen::GetScreen()->AddObserver(this);
-  ReportSinkAvailability(GetSinks());
 }
 
 WiredDisplayMediaRouteProvider::~WiredDisplayMediaRouteProvider() {
@@ -265,7 +264,6 @@ void WiredDisplayMediaRouteProvider::NotifyRouteObservers() const {
 void WiredDisplayMediaRouteProvider::NotifySinkObservers() {
   std::vector<MediaSinkInternal> sinks = GetSinks();
   device_count_metrics_.RecordDeviceCountsIfNeeded(sinks.size(), sinks.size());
-  ReportSinkAvailability(sinks);
   for (const auto& sink_query : sink_queries_)
     media_router_->OnSinksReceived(kProviderId, sink_query, sinks, {});
 }
@@ -292,12 +290,4 @@ std::vector<Display> WiredDisplayMediaRouteProvider::GetAvailableDisplays()
   return displays;
 }
 
-void WiredDisplayMediaRouteProvider::ReportSinkAvailability(
-    const std::vector<MediaSinkInternal>& sinks) {
-  mojom::MediaRouter::SinkAvailability sink_availability =
-      sinks.empty() ? mojom::MediaRouter::SinkAvailability::UNAVAILABLE
-                    : mojom::MediaRouter::SinkAvailability::PER_SOURCE;
-  media_router_->OnSinkAvailabilityUpdated(kProviderId, sink_availability);
-}
-
 }  // namespace media_router

chrome/browser/media/router/mojo/wired_display_media_route_provider.h

@@ -106,9 +106,6 @@ class WiredDisplayMediaRouteProvider : public mojom::MediaRouteProvider,
   // Sends the current list of sinks to each query in |sink_queries_|.
   void NotifySinkObservers();
 
-  // Notifies |media_router_| of the current sink availability.
-  void ReportSinkAvailability(const std::vector<MediaSinkInternal>& sinks);
-
   // Returns a list of available sinks. A display can be a sink if it is
   // secondary and does not mirror a primary display.
   std::vector<MediaSinkInternal> GetSinks() const;

chrome/browser/media/router/mojo/wired_display_media_route_provider_unittest.cc

@@ -157,41 +157,6 @@ TEST_F(WiredDisplayMediaRouteProviderTest, GetDisplaysAsSinks) {
   base::RunLoop().RunUntilIdle();
 }
 
-TEST_F(WiredDisplayMediaRouteProviderTest, NotifyOnDisplayChange) {
-  const std::string sink_id1 = GetSinkId(sink_display1_);
-  provider_pointer_->StartObservingMediaSinks(kPresentationSource);
-  base::RunLoop().RunUntilIdle();
-
-  // Add an external display. MediaRouter should be notified of the sink and the
-  // sink availability change.
-  provider_->set_all_displays({primary_display_, sink_display1_});
-  EXPECT_CALL(router_, OnSinkAvailabilityUpdated(
-                           mojom::MediaRouteProvider::Id::WIRED_DISPLAY,
-                           mojom::MediaRouter::SinkAvailability::PER_SOURCE));
-  EXPECT_CALL(
-      router_,
-      OnSinksReceived(mojom::MediaRouteProvider::Id::WIRED_DISPLAY, _, _, _))
-      .WillOnce(WithArg<2>(
-          Invoke([&sink_id1](const std::vector<MediaSinkInternal>& sinks) {
-            EXPECT_EQ(sinks.size(), 1u);
-            EXPECT_EQ(sinks[0].sink().id(), sink_id1);
-          })));
-  provider_->OnDisplayAdded(sink_display1_);
-  base::RunLoop().RunUntilIdle();
-
-  // Remove the external display. MediaRouter should be notified of the lack of
-  // sinks.
-  provider_->set_all_displays({primary_display_});
-  EXPECT_CALL(router_, OnSinkAvailabilityUpdated(
-                           mojom::MediaRouteProvider::Id::WIRED_DISPLAY,
-                           mojom::MediaRouter::SinkAvailability::UNAVAILABLE));
-  EXPECT_CALL(router_,
-              OnSinksReceived(mojom::MediaRouteProvider::Id::WIRED_DISPLAY, _,
-                              IsEmpty(), _));
-  provider_->OnDisplayRemoved(sink_display1_);
-  base::RunLoop().RunUntilIdle();
-}
-
 TEST_F(WiredDisplayMediaRouteProviderTest, NoSinksForNonPresentationSource) {
   EXPECT_CALL(router_,
               OnSinksReceived(kProviderId, kNonPresentationSource, _, _))