Fix checkdeps.py to check all the source directories in git checkouts.

tools/checkdeps/checkdeps.py

Index: tools/checkdeps/checkdeps.py
diff --git a/tools/checkdeps/checkdeps.py b/tools/checkdeps/checkdeps.py
index b175beaf92cf209e92f59f6eeba322d33c56484a..6c862776e7f151e30bbab204b1911a4b6301db69 100755
--- a/tools/checkdeps/checkdeps.py
+++ b/tools/checkdeps/checkdeps.py
@@ -416,7 +416,10 @@ def GetGitSourceDirectory(root):
                        pipes.quote(root))
   for line in popen_out.readlines():
     dir_name = os.path.join(root, os.path.dirname(line))
-    git_source_directory.add(dir_name)
+    # Add the directory as well as all the parent directories.
+    while dir_name != root:
+      git_source_directory.add(dir_name)
+      dir_name = os.path.dirname(dir_name)
   git_source_directory.add(root)
   return git_source_directory