NotForReview: Expose the global memory budget (chromium side)

content/browser/memory/memory_coordinator_impl.cc

Index: content/browser/memory/memory_coordinator_impl.cc
diff --git a/content/browser/memory/memory_coordinator_impl.cc b/content/browser/memory/memory_coordinator_impl.cc
index 0e2cfa92443f2aaef59cf197bbc9ed930400b58c..dbbf7c314d016b30d7b518a81be79dd0f718ab9b 100644
--- a/content/browser/memory/memory_coordinator_impl.cc
+++ b/content/browser/memory/memory_coordinator_impl.cc
@@ -89,6 +89,16 @@ class MemoryCoordinatorHandleImpl : public mojom::MemoryCoordinatorHandle {
 
   // mojom::MemoryCoordinatorHandle:
   void AddChild(mojom::ChildMemoryCoordinatorPtr child) override;
+  void GetGlobalBudgetHandle(
+      const GetGlobalBudgetHandleCallback& callback) override {
+    auto handle = coordinator_->global_budget_handle_->Clone(
+        mojo::SharedBufferHandle::AccessMode::READ_ONLY);
+    callback.Run(std::move(handle));
+  }
+  void SetGlobalBudgetUpdateInterval(uint32_t interval_ms) override {
+    base::TimeDelta interval = base::TimeDelta::FromMilliseconds(interval_ms);
+    coordinator_->condition_observer_->ScheduleUpdateCondition(interval);
+  }
 
   mojom::ChildMemoryCoordinatorPtr& child() { return child_; }
   mojo::Binding<mojom::MemoryCoordinatorHandle>& binding() { return binding_; }
@@ -151,10 +161,14 @@ MemoryCoordinatorImpl::MemoryCoordinatorImpl(
       memory_monitor_(std::move(memory_monitor)),
       condition_observer_(
           base::MakeUnique<MemoryConditionObserver>(this, task_runner)),
-      minimum_state_transition_period_(base::TimeDelta::FromSeconds(
-          kDefaultMinimumTransitionPeriodSeconds)) {
+      minimum_state_transition_period_(
+          base::TimeDelta::FromSeconds(kDefaultMinimumTransitionPeriodSeconds)),
+      global_budget_handle_(mojo::SharedBufferHandle::Create(sizeof(int64_t))),
+      global_budget_mapping_(global_budget_handle_->Map(sizeof(int64_t))) {
   DCHECK(memory_monitor_.get());
+  DCHECK(global_budget_mapping_.get());
   base::MemoryCoordinatorProxy::SetMemoryCoordinator(this);
+  UpdateGlobalBudget(-1);
 }
 
 MemoryCoordinatorImpl::~MemoryCoordinatorImpl() {
@@ -232,6 +246,16 @@ MemoryState MemoryCoordinatorImpl::GetCurrentMemoryState() const {
   return browser_memory_state_;
 }
 
+int64_t MemoryCoordinatorImpl::GetGlobalBudget() {
+  return *reinterpret_cast<int64_t*>(global_budget_mapping_.get());
+}
+
+void MemoryCoordinatorImpl::SetGlobalBudgetUpdateInterval(
+    uint32_t interval_ms) {
+  condition_observer_->ScheduleUpdateCondition(
+      base::TimeDelta::FromMilliseconds(interval_ms));
+}
+
 void MemoryCoordinatorImpl::ForceSetMemoryCondition(MemoryCondition condition,
                                                     base::TimeDelta duration) {
   UpdateConditionIfNeeded(condition);
@@ -309,6 +333,10 @@ void MemoryCoordinatorImpl::UpdateConditionIfNeeded(
   }
 }
 
+void MemoryCoordinatorImpl::UpdateGlobalBudget(int budget) {
+  *reinterpret_cast<int64_t*>(global_budget_mapping_.get()) = budget;
+}
+
 void MemoryCoordinatorImpl::DiscardTab() {
   if (delegate_)
     delegate_->DiscardTab();