[IndexedDB] Adding async tracing for renderer calls.

third_party/WebKit/Source/modules/indexeddb/IDBRequest.h

Index: third_party/WebKit/Source/modules/indexeddb/IDBRequest.h
diff --git a/third_party/WebKit/Source/modules/indexeddb/IDBRequest.h b/third_party/WebKit/Source/modules/indexeddb/IDBRequest.h
index 9f271b74ea499cc7318d796a7b5fdf5c67f007cd..11e61e25c45a35f924f99db2218ea81a5e5fadbd 100644
--- a/third_party/WebKit/Source/modules/indexeddb/IDBRequest.h
+++ b/third_party/WebKit/Source/modules/indexeddb/IDBRequest.h
@@ -31,6 +31,7 @@
 
 #include <memory>
 
+#include "base/macros.h"
 #include "bindings/core/v8/ScriptValue.h"
 #include "core/dom/DOMStringList.h"
 #include "core/dom/SuspendableObject.h"
@@ -46,6 +47,7 @@
 #include "platform/blob/BlobData.h"
 #include "platform/heap/Handle.h"
 #include "platform/wtf/HashMap.h"
+#include "platform/wtf/Time.h"
 #include "public/platform/WebBlobInfo.h"
 #include "public/platform/modules/indexeddb/WebIDBCursor.h"
 #include "public/platform/modules/indexeddb/WebIDBTypes.h"
@@ -65,7 +67,30 @@ class MODULES_EXPORT IDBRequest : public EventTargetWithInlineData,
   USING_GARBAGE_COLLECTED_MIXIN(IDBRequest);
 
  public:
-  static IDBRequest* Create(ScriptState*, IDBAny* source, IDBTransaction*);
+  // Records async tracing, starting on contruction and ending on destruction or
+  // a to |RecordAndReset()|.

[pwnall, 2017/05/25 23:04:25]

a call to?

[dmurph, 2017/05/31 19:26:25]

Done.

+  class AsyncTraceState {
+   public:
+    AsyncTraceState();
+    AsyncTraceState(const char* tracing_name, void*);
+    ~AsyncTraceState();
+    AsyncTraceState(AsyncTraceState&&);
+    IDBRequest::AsyncTraceState& operator=(IDBRequest::AsyncTraceState&&);
+
+    bool is_valid() const { return tracing_name_; }
+    void RecordAndReset();
+
+   private:
+    const char* tracing_name_ = nullptr;
+    void* id_;
+
+    DISALLOW_COPY_AND_ASSIGN(AsyncTraceState);
+  };
+
+  static IDBRequest* Create(ScriptState*,
+                            IDBAny* source,
+                            IDBTransaction*,
+                            AsyncTraceState);
   ~IDBRequest() override;
   DECLARE_VIRTUAL_TRACE();
 
@@ -153,8 +178,13 @@ class MODULES_EXPORT IDBRequest : public EventTargetWithInlineData,
     transit_blob_handles_ = std::move(blob_handles);
   }
 
+  void AssignNewMetrics(AsyncTraceState metrics) {
+    DCHECK(!metrics_.is_valid());
+    metrics_ = std::move(metrics);
+  }
+
  protected:
-  IDBRequest(ScriptState*, IDBAny* source, IDBTransaction*);
+  IDBRequest(ScriptState*, IDBAny* source, IDBTransaction*, AsyncTraceState);
   void EnqueueEvent(Event*);
   void DequeueEvent(Event*);
   virtual bool ShouldEnqueueEvent() const;
@@ -186,6 +216,8 @@ class MODULES_EXPORT IDBRequest : public EventTargetWithInlineData,
   Member<IDBAny> result_;
   Member<DOMException> error_;
 
+  AsyncTraceState metrics_;
+
   bool has_pending_activity_ = true;
   HeapVector<Member<Event>> enqueued_events_;