Restrict network process sandbox

   Restrict network process sandbox
       https://bugs.webkit.org/show_bug.cgi?id=134360

       Reviewed by Sam Weinig.

       Add more restrictions to the network process sandbox.

       * NetworkProcess/cocoa/NetworkProcessCocoa.mm:
       (WebKit::NetworkProcess::platformInitializeNetworkProcessCocoa):
 Always use the cache directory provided in the initialization parameters,
 and make sure we consume the cookie directory extension.
       * Resources/SandboxProfiles/ios/com.apple.WebKit.Networking.sb:
 Make the sandbox profile much more restrictive.
       * Shared/Network/NetworkProcessCreationParameters.cpp:
       (WebKit::NetworkProcessCreationParameters::encode):
       (WebKit::NetworkProcessCreationParameters::decode):
       * Shared/Network/NetworkProcessCreationParameters.h:
 The network process now requires an extension to access
 its cookie storage.
       * Shared/mac/SandboxUtilities.cpp:
       (WebKit::pathForProcessContainer):
       * Shared/mac/SandboxUtilities.h:
 We need to be able to get hold of our container so
 that we can get the correct cookie storage directory.
       * UIProcess/WebContext.cpp:
       (WebKit::WebContext::ensureNetworkProcess):
 We have to pass in the an extension for the cookie storage directory when
       initalising the network process
       * UIProcess/mac/WebContextMac.mm:
       (WebKit::WebContext::platformDefaultCookieStorageDirectory):
 Make sure we provide the correct location on IOS
       * WebProcess/cocoa/WebProcessCocoa.mm:
       (WebKit::WebProcess::platformInitializeWebProcess):
 Consume the cookie storage extension

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@170733 268f45cc-cd09-0410-ab3c-d52691b4dbfc