Generate all extension schema namespaces as "api" and instead vary the generated bundle names.

extensions/browser/api/bluetooth/bluetooth_api.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 EXTENSIONS_BROWSER_API_BLUETOOTH_BLUETOOTH_API_H_
 #define EXTENSIONS_BROWSER_API_BLUETOOTH_BLUETOOTH_API_H_
 
 #include <string>
 
 #include "base/memory/ref_counted.h"
@@ skipping 46 matching lines @@
   static const char* service_name() { return "BluetoothAPI"; }
   static const bool kServiceRedirectedInIncognito = true;
   static const bool kServiceIsNULLWhileTesting = true;
 
   content::BrowserContext* browser_context_;
 
   // Created lazily on first access.
   scoped_ptr<BluetoothEventRouter> event_router_;
 };
 
-namespace core_api {
+namespace api {
 
 class BluetoothGetAdapterStateFunction : public BluetoothExtensionFunction {
  public:
   DECLARE_EXTENSION_FUNCTION("bluetooth.getAdapterState",
                              BLUETOOTH_GETADAPTERSTATE)
 
  protected:
   ~BluetoothGetAdapterStateFunction() override;
 
   // BluetoothExtensionFunction:
@@ skipping 46 matching lines @@
   ~BluetoothStopDiscoveryFunction() override {}
 
   // BluetoothExtensionFunction:
   bool DoWork(scoped_refptr<device::BluetoothAdapter> adapter) override;
 
  private:
   void OnSuccessCallback();
   void OnErrorCallback();
 };
 
-}  // namespace core_api
+}  // namespace api
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_API_BLUETOOTH_BLUETOOTH_API_H_