Add a Content API around BrowserChildProcessHost, similar to what was done with ChildProcessHost....

content/public/browser/browser_child_process_host_iterator.h

+// 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.
+
+#ifndef CONTENT_PUBLIC_BROWSER_BROWSER_CHILD_PROCESS_HOST_ITERATOR_H_
+#define CONTENT_PUBLIC_BROWSER_BROWSER_CHILD_PROCESS_HOST_ITERATOR_H_
+#pragma once
+
+#include <list>
+
+#include "content/common/content_export.h"
+#include "content/public/common/process_type.h"
+
+class BrowserChildProcessHost;
+
+namespace IPC {
+class Message;
+}
+
+namespace content {
+
+class BrowserChildProcessHostDelegate;
+struct ChildProcessData;
+
+// This class allows iteration through either all child processes, or ones of a
+// specific type, depending on which constructor is used.  Note that this should
+// be done from the IO thread and that the iterator should not be kept around as
+// it may be invalidated on subsequent event processing in the event loop.
+class CONTENT_EXPORT BrowserChildProcessHostIterator {
+ public:
+  BrowserChildProcessHostIterator();
+  explicit BrowserChildProcessHostIterator(content::ProcessType type);
+
+  // These methods work on the current iterator object. Only call them if
+  // Done() returns false.
+  bool operator++();
+  bool Done();
+  const ChildProcessData& GetData();
+  bool Send(IPC::Message* message);
+  BrowserChildProcessHostDelegate* GetDelegate();
+
+ private:
+  bool all_;
+  content::ProcessType type_;
+  std::list<BrowserChildProcessHost*>::iterator iterator_;
+};
+
+// Helper class so that subclasses of BrowserChildProcessHostDelegate can be
+// iterated with no casting needing. Note that because of the components build,
+// this class can only be used by BCPHD implementations that live in content,
+// otherwise link errors will result.
+template <class T>
+class CONTENT_EXPORT BrowserChildProcessHostTypeIterator
+    : public BrowserChildProcessHostIterator {
+ public:
+  explicit BrowserChildProcessHostTypeIterator(content::ProcessType type)
+      : BrowserChildProcessHostIterator(type) {}
+  T* operator->() {
+    return static_cast<T*>(GetDelegate());
+  }
+  T* operator*() {
+    return static_cast<T*>(GetDelegate());
+  }
+};
+
+};  // namespace content
+
+#endif  // CONTENT_PUBLIC_BROWSER_BROWSER_CHILD_PROCESS_HOST_ITERATOR_H_