[blink/bindings] Remove dead code in ParkableStringManager.

Whether the renderer is backgrounded is not used anymore, no need to
track it.

Change-Id: I4547feceb362d5fba90fbabf0b3842862a2d6af1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2552404Reviewed-by: Kentaro Hara <haraken@chromium.org>
Commit-Queue: Benoit L <lizeb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#829658}

third_party/blink/renderer/platform/bindings/parkable_string_manager.cc

@@ -127,16 +127,6 @@ ParkableStringManager& ParkableStringManager::Instance() {
 
 ParkableStringManager::~ParkableStringManager() = default;
 
-void ParkableStringManager::SetRendererBackgrounded(bool backgrounded) {
-  DCHECK(IsMainThread());
-  backgrounded_ = backgrounded;
-}
-
-bool ParkableStringManager::IsRendererBackgrounded() const {
-  DCHECK(IsMainThread());
-  return backgrounded_;
-}
-
 bool ParkableStringManager::OnMemoryDump(
     base::trace_event::ProcessMemoryDump* pmd) {
   DCHECK(IsMainThread());
@@ -486,7 +476,6 @@ ParkableStringManager::Statistics ParkableStringManager::ComputeStatistics()
 }
 
 void ParkableStringManager::ResetForTesting() {
-  backgrounded_ = false;
   has_pending_aging_task_ = false;
   has_posted_unparking_time_accounting_task_ = false;
   did_register_memory_pressure_listener_ = false;
@@ -501,8 +490,7 @@ void ParkableStringManager::ResetForTesting() {
 }
 
 ParkableStringManager::ParkableStringManager()
-    : backgrounded_(false),
-      has_pending_aging_task_(false),
+    : has_pending_aging_task_(false),
       has_posted_unparking_time_accounting_task_(false),
       did_register_memory_pressure_listener_(false),
       allocator_for_testing_(nullptr) {}

third_party/blink/renderer/platform/bindings/parkable_string_manager.h

@@ -56,8 +56,6 @@ class PLATFORM_EXPORT ParkableStringManager {
   static ParkableStringManager& Instance();
   ~ParkableStringManager();
 
-  void SetRendererBackgrounded(bool backgrounded);
-  bool IsRendererBackgrounded() const;
   void PurgeMemory();
   // Number of parked and unparked strings. Public for testing.
   size_t Size() const;
@@ -125,7 +123,6 @@ class PLATFORM_EXPORT ParkableStringManager {
   void ResetForTesting();
   ParkableStringManager();
 
-  bool backgrounded_;
   bool has_pending_aging_task_;
   bool has_posted_unparking_time_accounting_task_;
   bool did_register_memory_pressure_listener_;

third_party/blink/renderer/platform/bindings/parkable_string_test.cc

@@ -699,24 +699,7 @@ TEST_F(ParkableStringTest, SynchronousToDisk) {
   EXPECT_TRUE(impl->is_on_disk());  // Synchronous writing.
 }
 
-TEST_F(ParkableStringTest, OnPurgeMemoryInBackground) {
-  ParkableString parkable = CreateAndParkAll();
-  ParkableStringManager::Instance().SetRendererBackgrounded(true);
-  EXPECT_TRUE(ParkableStringManager::Instance().IsRendererBackgrounded());
-
-  parkable.ToString();
-  EXPECT_FALSE(parkable.Impl()->is_parked());
-  EXPECT_TRUE(parkable.Impl()->has_compressed_data());
-
-  MemoryPressureListenerRegistry::Instance().OnPurgeMemory();
-  EXPECT_TRUE(parkable.Impl()->is_parked());
-
-  parkable.ToString();
-  EXPECT_TRUE(parkable.Impl()->has_compressed_data());
-}
-
-TEST_F(ParkableStringTest, OnPurgeMemoryInForeground) {
-  ParkableStringManager::Instance().SetRendererBackgrounded(false);
+TEST_F(ParkableStringTest, OnPurgeMemory) {
   ParkableString parkable1 = CreateAndParkAll();
   ParkableString parkable2(MakeLargeString('b').ReleaseImpl());
 

third_party/blink/renderer/platform/scheduler/main_thread/main_thread_scheduler_impl.cc

@@ -33,7 +33,6 @@
 #include "third_party/blink/public/common/page/launching_process_state.h"
 #include "third_party/blink/public/platform/scheduler/web_agent_group_scheduler.h"
 #include "third_party/blink/public/platform/scheduler/web_renderer_process_type.h"
-#include "third_party/blink/renderer/platform/bindings/parkable_string_manager.h"
 #include "third_party/blink/renderer/platform/instrumentation/resource_coordinator/renderer_resource_coordinator.h"
 #include "third_party/blink/renderer/platform/runtime_enabled_features.h"
 #include "third_party/blink/renderer/platform/scheduler/common/features.h"
@@ -1083,7 +1082,6 @@ void MainThreadSchedulerImpl::SetRendererBackgrounded(bool backgrounded) {
     main_thread_only().metrics_helper.OnRendererForegrounded(now);
   }
 
-  ParkableStringManager::Instance().SetRendererBackgrounded(backgrounded);
   memory_purge_manager_.SetRendererBackgrounded(backgrounded);
 }