Move impl of identity.LaunchWebAuthFlow() extension API to its own file

chrome/browser/extensions/api/identity/identity_api.h

Index: chrome/browser/extensions/api/identity/identity_api.h
diff --git a/chrome/browser/extensions/api/identity/identity_api.h b/chrome/browser/extensions/api/identity/identity_api.h
index 303885c6a07a160e8b3b181b677e2488ed43d5a7..6ee7f6117c82617e5097c5ab27085c8fa36ab802 100644
--- a/chrome/browser/extensions/api/identity/identity_api.h
+++ b/chrome/browser/extensions/api/identity/identity_api.h
@@ -18,6 +18,7 @@
 #include "build/build_config.h"
 #include "chrome/browser/extensions/api/identity/extension_token_key.h"
 #include "chrome/browser/extensions/api/identity/gaia_web_auth_flow.h"
+#include "chrome/browser/extensions/api/identity/identity_launch_web_auth_flow_function.h"
 #include "chrome/browser/extensions/api/identity/identity_mint_queue.h"
 #include "chrome/browser/extensions/api/identity/identity_signin_flow.h"
 #include "chrome/browser/extensions/api/identity/web_auth_flow.h"
@@ -331,33 +332,6 @@ class IdentityRemoveCachedAuthTokenFunction : public UIThreadExtensionFunction {
   ResponseAction Run() override;
 };
 
-class IdentityLaunchWebAuthFlowFunction : public ChromeAsyncExtensionFunction,
-                                          public WebAuthFlow::Delegate {
- public:
-  DECLARE_EXTENSION_FUNCTION("identity.launchWebAuthFlow",
-                             EXPERIMENTAL_IDENTITY_LAUNCHWEBAUTHFLOW);
-
-  IdentityLaunchWebAuthFlowFunction();
-
-  // Tests may override extension_id.
-  void InitFinalRedirectURLPrefixForTest(const std::string& extension_id);
-
- private:
-  ~IdentityLaunchWebAuthFlowFunction() override;
-  bool RunAsync() override;
-
-  // WebAuthFlow::Delegate implementation.
-  void OnAuthFlowFailure(WebAuthFlow::Failure failure) override;
-  void OnAuthFlowURLChange(const GURL& redirect_url) override;
-  void OnAuthFlowTitleChange(const std::string& title) override {}
-
-  // Helper to initialize final URL prefix.
-  void InitFinalRedirectURLPrefix(const std::string& extension_id);
-
-  std::unique_ptr<WebAuthFlow> auth_flow_;
-  GURL final_url_prefix_;
-};
-
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_IDENTITY_IDENTITY_API_H_