Disable intensive throttling when WebSerial holding an opened port.

This CL add WebSerial into `WebSchedulerTrackedFeature` and create
scheduling affecting feature handle when a SerialPort is activated. By
doing so a hidden page won't be intensively throttled when holding a
opened SerialPort.

Change-Id: I2343e663aa34d80a5c51a1dd79542536c6b0f739
Bug: 1442957
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4545501
Commit-Queue: Alvin Ji <alvinji@chromium.org>
Reviewed-by: Andrey Kosyakov <caseq@chromium.org>
Reviewed-by: Rakina Zata Amni <rakina@chromium.org>
Reviewed-by: Reilly Grant <reillyg@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1152871}

content/browser/devtools/protocol/page_handler.cc

@@ -1596,6 +1596,10 @@ Page::BackForwardCacheNotRestoredReason BlocklistedFeatureToProtocol(
       return Page::BackForwardCacheNotRestoredReasonEnum::Dummy;
     case WebSchedulerTrackedFeature::kAuthorizationHeader:
       return Page::BackForwardCacheNotRestoredReasonEnum::AuthorizationHeader;
+    case WebSchedulerTrackedFeature::kWebSerial:
+      // Currently we add WebSchedulerTrackedFeature::kWebSerial only for
+      // disabling aggressive throttling.
+      NOTREACHED_NORETURN();
   }
 }
 
@@ -1809,6 +1813,8 @@ Page::BackForwardCacheNotRestoredReasonType MapBlocklistedFeatureToType(
     case WebSchedulerTrackedFeature::kDummy:
     case WebSchedulerTrackedFeature::kAuthorizationHeader:
       return Page::BackForwardCacheNotRestoredReasonTypeEnum::Circumstantial;
+    case WebSchedulerTrackedFeature::kWebSerial:
+      NOTREACHED_NORETURN();
   }
 }
 

content/browser/renderer_host/back_forward_cache_impl.cc

@@ -240,6 +240,11 @@ constexpr WebSchedulerTrackedFeatures kAllowedFeatures = {
     // TODO(crbug.com/1357482): Figure out if this should be allowed.
     WebSchedulerTrackedFeature::kWebNfc};
 
+// WebSchedulerTrackedFeatures that do not affect back/forward cache, but
+// affects other scheduling policies (e.g. aggressive throttling).
+constexpr WebSchedulerTrackedFeatures kNonBackForwardCacheAffectingFeatures = {
+    WebSchedulerTrackedFeature::kWebSerial};
+
 // The BackForwardCache feature is controlled via an experiment. This function
 // returns the allowed URL list where it is enabled.
 std::string GetAllowedURLList() {
@@ -410,7 +415,8 @@ bool IsSameOriginForTreeResult(RenderFrameHostImpl* rfh,
 // static
 BlockListedFeatures BackForwardCacheImpl::GetAllowedFeatures(
     RequestedFeatures requested_features) {
-  WebSchedulerTrackedFeatures result = kAllowedFeatures;
+  WebSchedulerTrackedFeatures result =
+      Union(kAllowedFeatures, kNonBackForwardCacheAffectingFeatures);
   if (IsContentInjectionSupported()) {
     result.PutAll(kInjectionFeatures);
   }

third_party/blink/common/scheduler/web_scheduler_tracked_feature.cc

@@ -127,6 +127,8 @@ FeatureNames FeatureToNames(WebSchedulerTrackedFeature feature) {
       return {"AuthorizationHeader", "Authorization header used"};
     case WebSchedulerTrackedFeature::kIndexedDBEvent:
       return {"IndexedDBEvent", "IndexedDB event is pending"};
+    case WebSchedulerTrackedFeature::kWebSerial:
+      return {"WebSerial", "Serial port open"};
   }
   return {};
 }

third_party/blink/public/common/scheduler/web_scheduler_tracked_feature.h

@@ -128,12 +128,14 @@ enum class WebSchedulerTrackedFeature : uint32_t {
   // There is a pending IndexedDB event (e.g. versionchange event sent but the
   // connection is not closed yet) that requires the page not to enter BFCache.
   kIndexedDBEvent = 61,
-
+  // Aggressive throttling is disabled when a serial port is opened and
+  // re-enabled when the opened port is closed.
+  kWebSerial = 62,
   // Please keep in sync with WebSchedulerTrackedFeature in
   // tools/metrics/histograms/enums.xml. These values should not be renumbered.
 
   // NB: This enum is used in a bitmask, so kMaxValue must be less than 64.
-  kMaxValue = kIndexedDBEvent,
+  kMaxValue = kWebSerial,
 };
 
 using WebSchedulerTrackedFeatures =

third_party/blink/public/devtools_protocol/browser_protocol.pdl

@@ -8523,6 +8523,7 @@ domain Page
       IndexedDBEvent
       Dummy
       AuthorizationHeader
+      WebSerial
       # Disabled for RenderFrameHost reasons
       # See content/browser/renderer_host/back_forward_cache_disable.h for explanations.
       ContentSecurityHandler

third_party/blink/renderer/modules/serial/serial_port.cc

@@ -633,13 +633,19 @@ void SerialPort::OnOpen(
     return;
   }
 
+  auto* execution_context = GetExecutionContext();
+  feature_handle_for_scheduler_ =
+      execution_context->GetScheduler()->RegisterFeature(
+          SchedulingPolicy::Feature::kWebSerial,
+          SchedulingPolicy{SchedulingPolicy::DisableAggressiveThrottling()});
+
   port_.Bind(std::move(port),
-             GetExecutionContext()->GetTaskRunner(TaskType::kMiscPlatformAPI));
+             execution_context->GetTaskRunner(TaskType::kMiscPlatformAPI));
   port_.set_disconnect_handler(
       WTF::BindOnce(&SerialPort::OnConnectionError, WrapWeakPersistent(this)));
   client_receiver_.Bind(
       std::move(client_receiver),
-      GetExecutionContext()->GetTaskRunner(TaskType::kMiscPlatformAPI));
+      execution_context->GetTaskRunner(TaskType::kMiscPlatformAPI));
 
   open_resolver_->Resolve();
   open_resolver_ = nullptr;
@@ -687,6 +693,7 @@ void SerialPort::OnClose() {
   DCHECK(IsClosing());
   close_resolver_->Resolve();
   close_resolver_ = nullptr;
+  feature_handle_for_scheduler_.reset();
 }
 
 void SerialPort::OnForget(ScriptPromiseResolver* resolver) {

third_party/blink/renderer/modules/serial/serial_port.h

@@ -18,6 +18,7 @@
 #include "third_party/blink/renderer/platform/mojo/heap_mojo_receiver.h"
 #include "third_party/blink/renderer/platform/mojo/heap_mojo_remote.h"
 #include "third_party/blink/renderer/platform/mojo/heap_mojo_wrapper_mode.h"
+#include "third_party/blink/renderer/platform/scheduler/public/frame_scheduler.h"
 
 namespace base {
 class UnguessableToken;
@@ -130,6 +131,9 @@ class SerialPort final : public EventTargetWithInlineData,
   HeapHashSet<Member<ScriptPromiseResolver>> signal_resolvers_;
   // Resolver for the Promise returned by close().
   Member<ScriptPromiseResolver> close_resolver_;
+
+  FrameScheduler::SchedulingAffectingFeatureHandle
+      feature_handle_for_scheduler_;
 };
 
 }  // namespace blink

tools/metrics/histograms/enums.xml

@@ -111441,6 +111441,7 @@ Called by update_scheduler_enums.py.-->
   <int value="59" label="Keepalive request"/>
   <int value="60" label="AuthorizationHeader"/>
   <int value="61" label="IndexedDBEvent"/>
+  <int value="62" label="WebSerial"/>
 </enum>
 
 <enum name="WebShareMethod">