memory_coordinator: Discard tabs under critical memory condition

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 b403cf462dcf439def9fae164db4987440cc76c5..a8fd29d7b55026e2118f4dd2e4d369c86fe18561 100644
--- a/content/browser/memory/memory_coordinator_impl.cc
+++ b/content/browser/memory/memory_coordinator_impl.cc
@@ -277,6 +277,11 @@ MemoryState MemoryCoordinatorImpl::GetStateForProcess(
 void MemoryCoordinatorImpl::UpdateConditionIfNeeded(
     MemoryCondition next_condition) {
   DCHECK(CalledOnValidThread());
+
+  // Discard one tab when the system is under high memory pressure.
+  if (next_condition == MemoryCondition::CRITICAL)
+    DiscardTab();
+
   if (memory_condition_ == next_condition)
     return;
 
@@ -309,7 +314,6 @@ void MemoryCoordinatorImpl::UpdateConditionIfNeeded(
     // Set THROTTLED state to all clients/processes.
     UpdateBrowserStateAndNotifyStateToClients(MemoryState::THROTTLED);
     NotifyStateToChildren(MemoryState::THROTTLED);
-    // Idea: Start discarding tabs.
   }
 }