Update merge info now that we use Chromium 9.0.597.0

The V8 revision remains r5901

Note that this is a backwards merge from Chromium release 9.0.600.0
to 9.0.597.0, to align with the Chromium 9 stable release branch.

Change-Id: Ia5ca877bfa2cf2e01b46555e2fcca4f46c45e142
diff --git a/V8_MERGE_REVISION b/V8_MERGE_REVISION
index 4900304..ba5e70a 100644
--- a/V8_MERGE_REVISION
+++ b/V8_MERGE_REVISION
@@ -1,4 +1,4 @@
 We use a V8 revision that has been used for a Chromium release.
 
-http://src.chromium.org/svn/releases/9.0.600.0/DEPS
+http://src.chromium.org/svn/releases/9.0.597.0/DEPS
 http://v8.googlecode.com/svn/trunk@5901