Use updated signature for decode in empty decoder.

This allows chromium to build SkImageDecoder_empty.cpp
(https://codereview.chromium.org/15960015/) until Skia
has https://codereview.chromium.org/15806010/ (which
is a superset of this change).

R=robertphillips@google.com

Review URL: https://codereview.chromium.org/15742029

git-svn-id: http://skia.googlecode.com/svn/trunk@9321 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/ports/SkImageDecoder_empty.cpp b/src/ports/SkImageDecoder_empty.cpp
index 410eef1..43beb94 100644
--- a/src/ports/SkImageDecoder_empty.cpp
+++ b/src/ports/SkImageDecoder_empty.cpp
@@ -23,7 +23,7 @@
     return false;
 }
 
-bool SkImageDecoder::decode(SkStream*, SkBitmap* bitmap, SkBitmap::Config pref, Mode) {
+bool SkImageDecoder::decode(SkStream*, SkBitmap*, SkBitmap::Config, Mode, bool) {
     return false;
 }