Removed virtualenv from depot_tools

bootstrap/virtualenv/virtualenv_embedded/activate.fish

-# This file must be used with "source bin/activate.fish" *from fish* (http://fishshell.com)
-# you cannot run it directly
-
-function deactivate  -d "Exit virtualenv and return to normal shell environment"
-    # reset old environment variables
-    if test -n "$_OLD_VIRTUAL_PATH" 
-        set -gx PATH $_OLD_VIRTUAL_PATH
-        set -e _OLD_VIRTUAL_PATH
-    end
-    if test -n "$_OLD_VIRTUAL_PYTHONHOME"
-        set -gx PYTHONHOME $_OLD_VIRTUAL_PYTHONHOME
-        set -e _OLD_VIRTUAL_PYTHONHOME
-    end
-    
-    if test -n "$_OLD_FISH_PROMPT_OVERRIDE"
-        # set an empty local fish_function_path, so fish_prompt doesn't automatically reload
-        set -l fish_function_path
-        # erase the virtualenv's fish_prompt function, and restore the original
-        functions -e fish_prompt
-        functions -c _old_fish_prompt fish_prompt
-        functions -e _old_fish_prompt
-        set -e _OLD_FISH_PROMPT_OVERRIDE
-    end
-    
-    set -e VIRTUAL_ENV
-    if test "$argv[1]" != "nondestructive"
-        # Self destruct!
-        functions -e deactivate
-    end
-end
-
-# unset irrelevant variables
-deactivate nondestructive
-
-set -gx VIRTUAL_ENV "__VIRTUAL_ENV__"
-
-set -gx _OLD_VIRTUAL_PATH $PATH
-set -gx PATH "$VIRTUAL_ENV/__BIN_NAME__" $PATH
-
-# unset PYTHONHOME if set
-if set -q PYTHONHOME
-    set -gx _OLD_VIRTUAL_PYTHONHOME $PYTHONHOME
-    set -e PYTHONHOME
-end
-
-if test -z "$VIRTUAL_ENV_DISABLE_PROMPT"
-    # fish uses a function instead of an env var to generate the prompt.
-    
-    # copy the current fish_prompt function as the function _old_fish_prompt
-    functions -c fish_prompt _old_fish_prompt
-    
-    # with the original prompt function copied, we can override with our own.
-    function fish_prompt
-        # Prompt override?
-        if test -n "__VIRTUAL_PROMPT__"
-            printf "%s%s" "__VIRTUAL_PROMPT__" (set_color normal)
-            _old_fish_prompt
-            return
-        end
-        # ...Otherwise, prepend env
-        set -l _checkbase (basename "$VIRTUAL_ENV")
-        if test $_checkbase = "__"
-            # special case for Aspen magic directories
-            # see http://www.zetadev.com/software/aspen/
-            printf "%s[%s]%s " (set_color -b blue white) (basename (dirname "$VIRTUAL_ENV")) (set_color normal) 
-            _old_fish_prompt
-        else
-            printf "%s(%s)%s" (set_color -b blue white) (basename "$VIRTUAL_ENV") (set_color normal)
-            _old_fish_prompt
-        end
-    end 
-    
-    set -gx _OLD_FISH_PROMPT_OVERRIDE "$VIRTUAL_ENV"
-end