Make overriding BrowserContext::RegisterPrefs actually work

We were calling it before derived classes' vtables were set up. Now we wait to
call it until the BrowserContext is fully constructed.
Include gyp as a submodule

This makes it so you don't have to install gyp on your system before you
can build.
Merge pull request #28 from brightray/vendor-gyp

Include gyp as a submodule
Update libchromiumcontent to Chrome 29

* vendor/libchromiumcontent 5ffcb39...ccec3a4 (2):
  > Merge pull request #25 from brightray/29.0.1547.57
  > Switch back to using s3put on Linux
Update for utf_string_conversions.h move in Chrome 29
Update for move of MessageLoop into base namespace
Update for webkit header moves
Update utf_string_conversions.h path in another place
Merge pull request #29 from brightray/chrome-29

Update to Chrome 29
Update to latest libchromiumcontent

* vendor/libchromiumcontent ccec3a4...a56056d (1):
  > Stop exporting GURL symbols from test_support_chromiumcontent
Update to Chrome 30

* vendor/libchromiumcontent a56056d...bfb2d7b (1):
  > Merge pull request #27 from brightray/chrome-30
Update #includes for moves of string-related headers

See http://src.chromium.org/viewvc/chrome?view=revision&revision=205050.
Update for move of scoped_nsobject header and namespace

See http://src.chromium.org/viewvc/chrome?view=revision&revision=207616.
content::BrowserContext::GetPath is a const member function in Chrome 30

See http://src.chromium.org/viewvc/chrome?view=revision&revision=211931.
BrowserContext::GetSpeechRecognitionPreferences is gone in Chrome 30

See http://src.chromium.org/viewvc/chrome?view=revision&revision=210616.
BrowserContext::RequestMIDISysExPermission was added in Chrome 30

See http://src.chromium.org/viewvc/chrome?view=revision&revision=211437.
Add DevToolsFrontendHostDelegate indexing methods from Chrome 30

See http://src.chromium.org/viewvc/chrome?view=revision&revision=215622.
Update browser/media/* for Chrome 30

I took the latest versions of these files from chrome/browser/media,
then pared them down to remove all Chrome-isms and uses of UI to prompt
the user about allowing access to devices.
URLRequestContextStorage::set_http_server_properties takes a scoped_ptr in Chrome 30

See http://src.chromium.org/viewvc/chrome?view=revision&revision=212466.
Update ResourceContext for Chrome 30

See http://src.chromium.org/viewvc/chrome?view=revision&revision=215991.