Print git log in commit order

Use --topo-order to list commits in the order they
were actually committed.

TBR=tomfinegan@chromium.org

Review URL: https://codereview.chromium.org/560483002

git-svn-id: http://src.chromium.org/svn/trunk/deps/third_party/libvpx@291880 4ff67af0-8c30-449e-8e8b-ad334ec8d88c
diff --git a/update_libvpx.sh b/update_libvpx.sh
index c00b3b0..ff9c431 100755
--- a/update_libvpx.sh
+++ b/update_libvpx.sh
@@ -73,10 +73,10 @@
 # Output log for upstream from current hash.
 if [ -n "$prev_hash" ]; then
   echo "git log from upstream:"
-  pretty_git_log="$(git log --no-merges --pretty="%h %s" $prev_hash..$hash)"
+  pretty_git_log="$(git log --no-merges --topo-order --pretty="%h %s" $prev_hash..$hash)"
   if [ -z "$pretty_git_log" ]; then
     echo "No log found. Checking for reverts."
-    pretty_git_log="$(git log --no-merges --pretty="%h %s" $hash..$prev_hash)"
+    pretty_git_log="$(git log --no-merges --topo-order --pretty="%h %s" $hash..$prev_hash)"
   fi
   echo "$pretty_git_log"
 fi