Start off the Content API by moving content::ContentRendererClient to content\public\renderer.BU...

content/content.gyp

 # Copyright (c) 2011 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.
 
 {
   'variables': {
     'chromium_code': 1,  # Use higher warning level.
     'directxsdk_exists': '<!(python <(DEPTH)/build/dir_exists.py ../third_party/directxsdk)',
   },
   'includes': [
     '../build/win_precompile.gypi',
+    'content_api.gypi',
     'content_shell.gypi',
     'content_tests.gypi',
   ],
   'target_defaults': {
     'defines': ['CONTENT_IMPLEMENTATION'],
   },
   'conditions': [
    # In component mode, we build all of content as a single DLL.
    # However, in the static mode, we need to build content as multiple
    # targets in order to prevent dependencies from getting introduced
    # upstream unnecessarily (e.g., content_renderer depends on allocator
    # and chrome_exe depends on content_common but we don't want
    # chrome_exe to have to depend on allocator).
    # TODO(dpranke): Uncomment: ['component == "static_library"', {
    ['1 == 1', {
      'targets': [
       {'target_name': 'content',
        'type': 'none',
        'dependencies': [
+        'content_api',
         'content_app',
         'content_browser',
         'content_common',
         'content_gpu',
         'content_plugin',
         'content_ppapi_plugin',
         'content_renderer',
         'content_utility',
         'content_worker',
        ],
       },
+      {'target_name': 'content_api',
+       'type': 'none',
+       'includes': [
+          'content_api.gypi',
+        ],
+      },
       {'target_name': 'content_app',
        'type': 'static_library',
        'includes': [
           'content_app.gypi',
         ],
        'dependencies': [
           'content_common',
         ],
       },
       {'target_name': 'content_browser',
@@ skipping 127 matching lines @@
        }],
       ],
     },
     { # component != static_library
      'target_defaults': {
      },
      'targets': [
       {'target_name': 'content',
        'type': 'shared_library',
        'includes': [
+        'content_api.gypi',
         'content_app.gypi',
         'content_browser.gypi',
         'content_common.gypi',
         'content_gpu.gypi',
         'content_plugin.gypi',
         'content_ppapi_plugin.gypi',
         'content_renderer.gypi',
         'content_utility.gypi',
         'content_worker.gypi',
        ],
       },
+      {'target_name': 'content_api',
+       'type': 'none',
+      },
       {'target_name': 'content_app',
        'type': 'none',
        'dependencies': ['content', 'content_browser'],
       },
       {'target_name': 'content_browser',
        'type': 'none',
        'dependencies': ['content'],
       },
       {'target_name': 'content_common',
        'type': 'none',
@@ skipping 21 matching lines @@
       },
       {'target_name': 'content_worker',
        'type': 'none',
        'dependencies': ['content'],
       },
      ],
     },
    ],
   ],
 }