DevTools: Support async call stacks for FileSystem API (part 1).

Source/modules/filesystem/DOMFileSystem.h

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 87 matching lines @@
 
     template <typename CB, typename CBArg>
     void scheduleCallback(PassOwnPtr<CB> callback, const CBArg& callbackArg)
     {
         scheduleCallback(executionContext(), callback, callbackArg);
     }
 
 private:
     DOMFileSystem(ExecutionContext*, const String& name, FileSystemType, const KURL& rootURL);
 
+    class DispatchCallbackTaskBase : public ExecutionContextTask {
+    public:
+        DispatchCallbackTaskBase()
+            : m_taskName("FileSystem")
+        {
+        }
+
+        virtual const String& taskNameForInstrumentation() const OVERRIDE

[yurys, 2014/07/14 14:55:54]

Why do we return constr String& rather than String from this method in
ExecutionContextTask?

+        {
+            return m_taskName;
+        }
+
+    private:
+        const String m_taskName;
+    };
+
     // A helper template to schedule a callback task.
     template <typename CB, typename CBArg>
-    class DispatchCallbackRefPtrArgTask FINAL : public ExecutionContextTask {
+    class DispatchCallbackRefPtrArgTask FINAL : public DispatchCallbackTaskBase {
     public:
         DispatchCallbackRefPtrArgTask(PassOwnPtr<CB> callback, PassRefPtrWillBeRawPtr<CBArg> arg)
             : m_callback(callback)
             , m_callbackArg(arg)
         {
         }
 
         virtual void performTask(ExecutionContext*) OVERRIDE
         {
             m_callback->handleEvent(m_callbackArg.get());
         }
 
     private:
         OwnPtr<CB> m_callback;
         RefPtrWillBePersistent<CBArg> m_callbackArg;
     };
 
     template <typename CB, typename CBArg>
-    class DispatchCallbackPtrArgTask FINAL : public ExecutionContextTask {
+    class DispatchCallbackPtrArgTask FINAL : public DispatchCallbackTaskBase {
     public:
         DispatchCallbackPtrArgTask(PassOwnPtr<CB> callback, CBArg* arg)
             : m_callback(callback)
             , m_callbackArg(arg)
         {
         }
 
         virtual void performTask(ExecutionContext*) OVERRIDE
         {
             m_callback->handleEvent(m_callbackArg.get());
         }
 
     private:
         OwnPtr<CB> m_callback;
         Persistent<CBArg> m_callbackArg;
     };
 
     template <typename CB, typename CBArg>
-    class DispatchCallbackNonPtrArgTask FINAL : public ExecutionContextTask {
+    class DispatchCallbackNonPtrArgTask FINAL : public DispatchCallbackTaskBase {
     public:
         DispatchCallbackNonPtrArgTask(PassOwnPtr<CB> callback, const CBArg& arg)
             : m_callback(callback)
             , m_callbackArg(arg)
         {
         }
 
         virtual void performTask(ExecutionContext*) OVERRIDE
         {
             m_callback->handleEvent(m_callbackArg);
         }
 
     private:
         OwnPtr<CB> m_callback;
         CBArg m_callbackArg;
     };
 
     template <typename CB>
-    class DispatchCallbackNoArgTask FINAL : public ExecutionContextTask {
+    class DispatchCallbackNoArgTask FINAL : public DispatchCallbackTaskBase {
     public:
         DispatchCallbackNoArgTask(PassOwnPtr<CB> callback)
             : m_callback(callback)
         {
         }
 
         virtual void performTask(ExecutionContext*) OVERRIDE
         {
             m_callback->handleEvent();
         }
@@ skipping 41 matching lines @@
 void DOMFileSystem::scheduleCallback(ExecutionContext* executionContext, PassOwnPtr<CB> callback)
 {
     ASSERT(executionContext->isContextThread());
     if (callback)
         executionContext->postTask(adoptPtr(new DispatchCallbackNoArgTask<CB>(callback)));
 }
 
 } // namespace
 
 #endif // DOMFileSystem_h