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

extensions/browser/api/document_scan/mock_document_scan_interface.h

 // Copyright 2014 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_DOCUMENT_SCAN_MOCK_DOCUMENT_SCAN_INTERFACE_H_
 #define EXTENSIONS_BROWSER_API_DOCUMENT_SCAN_MOCK_DOCUMENT_SCAN_INTERFACE_H_
 
 #include <string>
 
 #include <gmock/gmock.h>
 
 #include "extensions/browser/api/document_scan/document_scan_interface.h"
 
 namespace extensions {
 
-namespace core_api {
+namespace api {
 
 class MockDocumentScanInterface : public DocumentScanInterface {
  public:
   MockDocumentScanInterface();
   ~MockDocumentScanInterface() override;
 
   MOCK_METHOD4(Scan,
                void(const std::string& scanner_name,
                     ScanMode mode,
                     int resolution_dpi,
                     const ScanResultsCallback& callback));
   MOCK_METHOD1(ListScanners, void(const ListScannersResultsCallback& callback));
   MOCK_CONST_METHOD0(GetImageMimeType, std::string());
 };
 
-}  // namespace core_api
+}  // namespace api
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_API_DOCUMENT_SCAN_MOCK_DOCUMENT_SCAN_INTERFACE_H_