Add delegate and factory function for ChildMemoryCoordinator

content/renderer/render_thread_impl.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/renderer/render_thread_impl.h"
 
 #include <algorithm>
 #include <limits>
 #include <map>
 #include <utility>
@@ skipping 803 matching lines @@
       base::Bind(&RenderThreadImpl::OnMemoryPressure, base::Unretained(this)),
       base::Bind(&RenderThreadImpl::OnSyncMemoryPressure,
                  base::Unretained(this))));
 
   if (memory_coordinator::IsEnabled()) {
     // TODO(bashi): Revisit how to manage the lifetime of
     // ChildMemoryCoordinatorImpl.
     // https://codereview.chromium.org/2094583002/#msg52
     memory_coordinator::mojom::MemoryCoordinatorHandlePtr parent_coordinator;
     GetRemoteInterfaces()->GetInterface(mojo::GetProxy(&parent_coordinator));
-    memory_coordinator_.reset(
-        new memory_coordinator::ChildMemoryCoordinatorImpl(
-            std::move(parent_coordinator)));
+    memory_coordinator_ = memory_coordinator::CreateChildMemoryCoordinator(
+        std::move(parent_coordinator), this);
   }
 
   int num_raster_threads = 0;
   std::string string_value =
       command_line.GetSwitchValueASCII(switches::kNumRasterThreads);
   bool parsed_num_raster_threads =
       base::StringToInt(string_value, &num_raster_threads);
   DCHECK(parsed_num_raster_threads) << string_value;
   DCHECK_GT(num_raster_threads, 0);
 
@@ skipping 1372 matching lines @@
   if (!RendererIsHidden() &&
       v8_memory_pressure_level == v8::MemoryPressureLevel::kCritical)
     v8_memory_pressure_level = v8::MemoryPressureLevel::kModerate;
 
   blink::mainThreadIsolate()->MemoryPressureNotification(
       v8_memory_pressure_level);
   blink::MemoryPressureNotificationToWorkerThreadIsolates(
       v8_memory_pressure_level);
 }
 
+// Note that this would be called only when memory_coordinator is enabled.
+// OnSyncMemoryPressure() is never called in that case.
+void RenderThreadImpl::OnTrimMemoryImmediately() {
+  if (blink::mainThreadIsolate()) {
+    blink::mainThreadIsolate()->MemoryPressureNotification(
+        v8::MemoryPressureLevel::kCritical);
+    blink::MemoryPressureNotificationToWorkerThreadIsolates(
+        v8::MemoryPressureLevel::kCritical);
+  }
+}
+
+
 }  // namespace content