Set up binary artifact downloading hook

DEPS

Index: DEPS
diff --git a/DEPS b/DEPS
index 82cdea64928b52f2af75f403d2ecd25e99fca4d3..420168425a603a1b1cccaee9e4e5991aaa04725a 100644
--- a/DEPS
+++ b/DEPS
@@ -161,4 +161,24 @@ hooks = [
         'src/third_party/binutils/download.py',
     ],
   },
+  # Pull the mojo_shell binary based on //third_party/mojo/MOJO_VERSION
+  {
+    'name': 'download_mojo_shell',
+    'pattern': '',
+    'action': [ 'python',
+                'src/third_party/mojo/src/mojo/public/tools/download_shell_binary.py',
+                '--tools-directory=../../../../../../tools',
+                '--version-file=../../../../MOJO_VERSION',
+              ],
+  },
+  # Pull the archiecture (sic) independent blobs
+  {
+    'name': 'download_archiecture_independent_frameworks',
+    'pattern': '',
+    'action': [ 'python',
+                'src/third_party/mojo/src/mojo/public/tools/download_archiecture_independent_frameworks.py',
+                '--tools-directory=../../../../../../tools',
+                '--version-file=../../../../MOJO_VERSION',
+              ],
+  },
 ]