Implement GCController::CollectAll

content/shell/renderer/gc_controller.cc

 // Copyright 2014 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/shell/renderer/gc_controller.h"
 
 #include "gin/arguments.h"
 #include "gin/handle.h"
 #include "gin/object_template_builder.h"
 #include "third_party/WebKit/public/web/WebFrame.h"
@@ skipping 21 matching lines @@
 }
 
 GCController::GCController() {}
 
 GCController::~GCController() {}
 
 gin::ObjectTemplateBuilder GCController::GetObjectTemplateBuilder(
     v8::Isolate* isolate) {
   return gin::Wrappable<GCController>::GetObjectTemplateBuilder(isolate)
       .SetMethod("collect", &GCController::Collect)
+      .SetMethod("collectAll", &GCController::CollectAll)
       .SetMethod("minorCollect", &GCController::MinorCollect);
 }
 
 void GCController::Collect(const gin::Arguments& args) {
   args.isolate()->RequestGarbageCollectionForTesting(
       v8::Isolate::kFullGarbageCollection);
 }
 
+void GCController::CollectAll(const gin::Arguments& args) {
+  // In order to collect a DOM wrapper, two GC cycles are needed.
+  // In the first GC cycle, a weak callback of the DOM wrapper is called back
+  // and the weak callback disposes a persistent handle to the DOM wrapper.
+  // In the second GC cycle, the DOM wrapper is reclaimed.
+  // Given that two GC cycles are needed to collect one DOM wrapper,
+  // more than two GC cycles are needed to collect all DOM wrappers
+  // that are chained. Seven GC cycles look enough in most tests.
+  for (int i = 0; i < 7; i++) {
+    args.isolate()->RequestGarbageCollectionForTesting(
+        v8::Isolate::kFullGarbageCollection);
+  }
+}
+
 void GCController::MinorCollect(const gin::Arguments& args) {
   args.isolate()->RequestGarbageCollectionForTesting(
       v8::Isolate::kMinorGarbageCollection);
 }
 
 }  // namespace content