cc: defer dumping display item lists till trace is stopped

Also, only trace individual display items if disabled-by-default-cc.debug.display_items is enabled, as these happen to
result in HUGE traces.

BUG=497796
CQ_INCLUDE_TRYBOTS=tryserver.blink:linux_blink_rel

Review URL: https://codereview.chromium.org/1151653005

Cr-Commit-Position: refs/heads/master@{#335244}

1 files changed, 42 insertions, 0 deletions

diff --git a/cc/debug/traced_display_item_list.h b/cc/debug/traced_display_item_list.h
new file mode 100644
index 0000000..f7caa04
--- /dev/null
+++ b/cc/debug/traced_display_item_list.h
@@ -0,0 +1,42 @@
+// Copyright 2015 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.
+
+#ifndef CC_DEBUG_TRACED_DISPLAY_ITEM_LIST_H_
+#define CC_DEBUG_TRACED_DISPLAY_ITEM_LIST_H_
+
+#include <string>
+
+#include "base/memory/ref_counted.h"
+#include "base/trace_event/trace_event.h"
+#include "cc/debug/traced_value.h"
+
+namespace cc {
+
+class DisplayItemList;
+
+class TracedDisplayItemList
+    : public base::trace_event::ConvertableToTraceFormat {
+ public:
+  static scoped_refptr<ConvertableToTraceFormat> AsTraceableDisplayItemList(
+      scoped_refptr<const DisplayItemList> list,
+      bool include_items) {
+    return scoped_refptr<ConvertableToTraceFormat>(
+        new TracedDisplayItemList(list, include_items));
+  }
+  void AppendAsTraceFormat(std::string* out) const override;
+
+ private:
+  explicit TracedDisplayItemList(scoped_refptr<const DisplayItemList> list,
+                                 bool include_items);
+  ~TracedDisplayItemList() override;
+
+  scoped_refptr<const DisplayItemList> display_item_list_;
+  bool include_items_;
+
+  DISALLOW_COPY_AND_ASSIGN(TracedDisplayItemList);
+};
+
+}  // namespace cc
+
+#endif  // CC_DEBUG_TRACED_DISPLAY_ITEM_LIST_H_