memory coordinator: Set variation parameters if available

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 c5bf7f1e8afb655fbc89da76a044745565a69ae9..87ea58303b49163b2fa4c7198a6edbb9d54a4f93 100644
--- a/content/browser/memory/memory_coordinator_impl.cc
+++ b/content/browser/memory/memory_coordinator_impl.cc
@@ -138,17 +138,7 @@ MemoryCoordinatorImpl::MemoryCoordinatorImpl(
   DCHECK(memory_monitor_.get());
   update_state_callback_ = base::Bind(&MemoryCoordinatorImpl::UpdateState,
                                       weak_ptr_factory_.GetWeakPtr());
-
-  // Set initial parameters for calculating the global state.
-  expected_renderer_size_ = kDefaultExpectedRendererSizeMB;
-  new_renderers_until_throttled_ = kDefaultNewRenderersUntilThrottled;
-  new_renderers_until_suspended_ = kDefaultNewRenderersUntilSuspended;
-  new_renderers_back_to_normal_ = kDefaultNewRenderersBackToNormal;
-  new_renderers_back_to_throttled_ = kDefaultNewRenderersBackToThrottled;
-  minimum_transition_period_ =
-      base::TimeDelta::FromSeconds(kDefaultMinimumTransitionPeriodSeconds);
-  monitoring_interval_ =
-      base::TimeDelta::FromSeconds(kDefaultMonitoringIntervalSeconds);
+  InitializeParameters();
 }
 
 MemoryCoordinatorImpl::~MemoryCoordinatorImpl() {}
@@ -221,25 +211,25 @@ base::MemoryState MemoryCoordinatorImpl::CalculateNextState() {
   if (available <= 0)
     return MemoryState::SUSPENDED;
 
-  int expected_renderer_count = available / expected_renderer_size_;
+  int expected_renderer_count = available / params_.expected_renderer_size;
 
   switch (current_state_) {
     case MemoryState::NORMAL:
-      if (expected_renderer_count <= new_renderers_until_suspended_)
+      if (expected_renderer_count <= params_.new_renderers_until_suspended)
         return MemoryState::SUSPENDED;
-      if (expected_renderer_count <= new_renderers_until_throttled_)
+      if (expected_renderer_count <= params_.new_renderers_until_throttled)
         return MemoryState::THROTTLED;
       return MemoryState::NORMAL;
     case MemoryState::THROTTLED:
-      if (expected_renderer_count <= new_renderers_until_suspended_)
+      if (expected_renderer_count <= params_.new_renderers_until_suspended)
         return MemoryState::SUSPENDED;
-      if (expected_renderer_count >= new_renderers_back_to_normal_)
+      if (expected_renderer_count >= params_.new_renderers_back_to_normal)
         return MemoryState::NORMAL;
       return MemoryState::THROTTLED;
     case MemoryState::SUSPENDED:
-      if (expected_renderer_count >= new_renderers_back_to_normal_)
+      if (expected_renderer_count >= params_.new_renderers_back_to_normal)
         return MemoryState::NORMAL;
-      if (expected_renderer_count >= new_renderers_back_to_throttled_)
+      if (expected_renderer_count >= params_.new_renderers_back_to_throttled)
         return MemoryState::THROTTLED;
       return MemoryState::SUSPENDED;
     case MemoryState::UNKNOWN:
@@ -269,9 +259,9 @@ void MemoryCoordinatorImpl::UpdateState() {
     RecordStateChange(prev_state, next_state, now - prev_last_state_change);
     NotifyStateToClients();
     NotifyStateToChildren();
-    ScheduleUpdateState(minimum_transition_period_);
+    ScheduleUpdateState(params_.minimum_transition_period);
   } else {
-    ScheduleUpdateState(monitoring_interval_);
+    ScheduleUpdateState(params_.monitoring_interval);
   }
 }
 
@@ -320,6 +310,21 @@ void MemoryCoordinatorImpl::ScheduleUpdateState(base::TimeDelta delta) {
   task_runner_->PostDelayedTask(FROM_HERE, update_state_callback_, delta);
 }
 
+void MemoryCoordinatorImpl::InitializeParameters() {
+  params_.expected_renderer_size = kDefaultExpectedRendererSizeMB;
+  params_.new_renderers_until_throttled = kDefaultNewRenderersUntilThrottled;
+  params_.new_renderers_until_suspended = kDefaultNewRenderersUntilSuspended;
+  params_.new_renderers_back_to_normal = kDefaultNewRenderersBackToNormal;
+  params_.new_renderers_back_to_throttled = kDefaultNewRenderersBackToThrottled;
+  params_.minimum_transition_period =
+      base::TimeDelta::FromSeconds(kDefaultMinimumTransitionPeriodSeconds);
+  params_.monitoring_interval =
+      base::TimeDelta::FromSeconds(kDefaultMonitoringIntervalSeconds);
+
+  if (delegate())
+    delegate()->OverrideParameters(&params_);
+}
+
 bool MemoryCoordinatorImpl::ValidateParameters() {
   return (new_renderers_until_throttled_ > new_renderers_until_suspended_) &&
       (new_renderers_back_to_normal_ > new_renderers_back_to_throttled_) &&