Remove UI_DEVTOOLS_EXPORT from class and add it to static methods

The error was caused because static methods in devtools_server.h were
not marked UI_DEVTOOLS_EXPORT. We cannot mark them as such if the whole
class is already marked. Therefore, we need to remove the export from the
class and add it to the static methods.

BUG=669352

Review-Url: https://codereview.chromium.org/2560013002
Cr-Commit-Position: refs/heads/master@{#437338}

components/ui_devtools/devtools_server.h

@@ -20,19 +20,18 @@
 namespace ui {
 namespace devtools {
 
-class UI_DEVTOOLS_EXPORT UiDevToolsServer
-    : public NON_EXPORTED_BASE(net::HttpServer::Delegate) {
+class UiDevToolsServer : public net::HttpServer::Delegate {
  public:
   ~UiDevToolsServer() override;
 
   // Returns an empty unique_ptr if ui devtools flag isn't enabled or if a
   // server instance has already been created.
-  static std::unique_ptr<UiDevToolsServer> Create(
+  static UI_DEVTOOLS_EXPORT std::unique_ptr<UiDevToolsServer> Create(
       scoped_refptr<base::SingleThreadTaskRunner> io_thread_task_runner);
 
   // Returns a list of attached UiDevToolsClient name + URL
   using NameUrlPair = std::pair<std::string, std::string>;
-  static std::vector<NameUrlPair> GetClientNamesAndUrls();
+  static UI_DEVTOOLS_EXPORT std::vector<NameUrlPair> GetClientNamesAndUrls();
 
   void AttachClient(std::unique_ptr<UiDevToolsClient> client);
   void SendOverWebSocket(int connection_id, const String& message);