Enable component build for browser_context_keyed_service.

components/browser_context_keyed_service/dependency_graph.h

 // Copyright 2013 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 COMPONENTS_BROWSER_CONTEXT_KEYED_SERVICE_DEPENDENCY_GRAPH_H_
 #define COMPONENTS_BROWSER_CONTEXT_KEYED_SERVICE_DEPENDENCY_GRAPH_H_
 
 #include <map>
 #include <string>
 #include <vector>
 
 #include "base/callback.h"
 #include "base/compiler_specific.h"
+#include "components/browser_context_keyed_service/browser_context_keyed_service_export.h"
 
 class DependencyNode;
 
 // Dynamic graph of dependencies between nodes.
-class DependencyGraph {
+class BROWSER_CONTEXT_KEYED_SERVICE_EXPORT DependencyGraph {
  public:
   DependencyGraph();
   ~DependencyGraph();
 
   // Adds/Removes a node from our list of live nodes. Removing will
   // also remove live dependency links.
   void AddNode(DependencyNode* node);
   void RemoveNode(DependencyNode* node);
 
   // Adds a dependency between two nodes.
@@ skipping 29 matching lines @@
   EdgeMap edges_;
 
   // Cached construction order (needs rebuild with BuildConstructionOrder
   // when empty).
   std::vector<DependencyNode*> construction_order_;
 
   DISALLOW_COPY_AND_ASSIGN(DependencyGraph);
 };
 
 #endif  // COMPONENTS_BROWSER_CONTEXT_KEYED_SERVICE_DEPENDENCY_GRAPH_H_