Fix SCons-based webkit build on Windows (broken by the Linux command-line changes) by using portable SCons idioms: * Side-step command-line differences by using a Python function as a   build action to generate a .h file by surrounding the contents of   the yacc-generated .hpp file with a #ifndef-#define-#endif guard. * Use the pre-defined Delete() ActionFactory to let SCons delete the   .hpp file directly, instead of calling "rm" to do it. TBR: evanm
Fix SCons-based webkit build on Windows (broken by the Linux
command-line changes) by using portable SCons idioms:
* Side-step command-line differences by using a Python function as a
  build action to generate a .h file by surrounding the contents of
  the yacc-generated .hpp file with a #ifndef-#define-#endif guard.
* Use the pre-defined Delete() ActionFactory to let SCons delete the
  .hpp file directly, instead of calling "rm" to do it.
TBR: evanm

git-svn-id: http://src.chromium.org/svn/trunk/src@1523 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 8309bb30cbfdf5c77cab5e79b7e8913c24def739
meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser