Add hook to download Fuchsia SDK

DEPS

Index: DEPS
diff --git a/DEPS b/DEPS
index 52a209de8fdf7dae7888243bd219335a12c1be1e..a9315ecc8e88f666cacd1f4526d9c6222d002ba6 100644
--- a/DEPS
+++ b/DEPS
@@ -1160,6 +1160,20 @@ hooks = [
   },
 ]
 
+hooks_os = {
+  'fuchsia': [
+    {
+      'name': 'fuchsia_sdk',
+      'pattern': '.',
+      'action': [
+        'python',
+        'src/build/fuchsia/update_sdk.py',
+        '3886a632c4a472fa7ef9eab35b45b63359e387fa',
+      ],
+    },
+  ],

[Nico, 2017/05/15 20:20:02]

Can you add a TODO here (on me, if you want) to move some of the android hooks
to down here?

[scottmg, 2017/05/15 20:34:47]

Done.

+}
+
 recursedeps = [
   # buildtools provides clang_format, libc++, and libc++abi
   'src/buildtools',