Roll DEPS for v8 to d3f97a9. Regular weekly roll.

TBR=tsepez@chromium.org

Review URL: https://codereview.chromium.org/1407643002 .
diff --git a/DEPS b/DEPS
index 85f5090..e1c4fa3 100644
--- a/DEPS
+++ b/DEPS
@@ -17,7 +17,7 @@
      "https://chromium.googlesource.com/external/googletest.git@8245545b6dc9c4703e6496d1efd19e975ad2b038",
 
   "v8":
-    "https://chromium.googlesource.com/v8/v8.git@9081ee11af0311aecb152bfe80330fc1bf6085e6",
+    "https://chromium.googlesource.com/v8/v8.git@d3f97a972ffe37989fed2794d07e33f7c25f651c",
 
   "v8/third_party/icu":
     "https://chromium.googlesource.com/chromium/deps/icu46",