Check in a little toy that graphs history of words in the source.

tools/git/README

Index: tools/git/README
diff --git a/tools/git/README b/tools/git/README
index 18d6da7e243e0fcdf3b42e2412dac1f0194d2170..7f8e363dee052fd1649614d18bc411bf05bcd8d6 100644
--- a/tools/git/README
+++ b/tools/git/README
@@ -1,8 +1,16 @@
-This directory contains some helpful Git hooks.
+This directory contains some helpful Git tools.
 
-Currently, they warn you about DEPS modifications so you will remember
+post-checkout and post-merge
+============================
+These hooks warn you about DEPS modifications so you will remember
 to run "gclient sync".
 
 To install these Git hooks, create symlinks like so:
   ln -s $(pwd)/post-checkout $(git rev-parse --git-dir)/hooks
   ln -s $(pwd)/post-merge    $(git rev-parse --git-dir)/hooks
+
+
+git-graph
+=========
+Create a graph of the recent history of occurences of a grep
+expression in the project.