Previously, we used to verify the snapshot script by running it in a
new, empty context (similar to the one that `mksnapshot` creates when
generating the startup blob).
However, this context was being created using the Node version that
`script/build` was executed with. Such version may not match the Node
version shipped with Electron, and could thus cause the build script to
report "false negatives" when verifying the snapshot script. For
instance, running `script/build` with Node 4 would cause it to throw an
error when encountering keywords like `async`/`await`, even if they're
100% supported in Electron 1.6.9.
With this commit we are changing the snapshot verification code to use
the Node version bundled in Electron in order to avoid the
aforementioned mismatches.
The xdg desktop file specification allows for icons to be either a
absolute path just a name. If the name is not an absolute path,
a icon from a icon theme will be used. This commit changes the
desktop file to use a icon name and adds the icons to the default
theme (hicolor). This allows the user to choose an alternative icons
theme that will override the default icon.
The relevant specs:
https://specifications.freedesktop.org/desktop-entry-spec/latest/ar01s05.html
> Icon to display in file manager, menus, etc. If the name is an
> absolute path, the given file will be used. If the name is not
> an absolute path, the algorithm described in the Icon Theme
> Specification will be used to locate the icon.
https://specifications.freedesktop.org/icon-theme-spec/latest/ar01s07.html
> Installing Application Icons: [...] Minimally you should install a
> 48x48 icon in the hicolor theme. This means installing a PNG file
> in $prefix/share/icons/hicolor/48x48/apps.
https://specifications.freedesktop.org/icon-theme-spec/latest/ar01s03.html
> Icons and themes are looked for in a set of directories. By
> default, apps should look in $HOME/.icons (for backwards
> compatibility), in $XDG_DATA_DIRS/icons and in
> /usr/share/pixmaps (in that order).
https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html#variables
> $XDG_DATA_DIRS defines the preference-ordered set of base
> directories to search for data files in addition to the $XDG_DATA_HOME
> base directory. The directories in $XDG_DATA_DIRS should be
> seperated with a colon ':'.
> If $XDG_DATA_DIRS is either not set or empty, a value equal to
> /usr/local/share/:/usr/share/ should be used.
