Move code to dump GrSurface as a png to helper files

src/core/SkImagesSupport.h

Index: src/core/SkImagesSupport.h
diff --git a/src/core/SkImagesSupport.h b/src/core/SkImagesSupport.h
new file mode 100644
index 0000000000000000000000000000000000000000..a3e32f8a156ceaedb352673526a138abff1cae14
--- /dev/null
+++ b/src/core/SkImagesSupport.h
@@ -0,0 +1,22 @@
+/*
+ * Copyright 2014 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef SkImagesSupport_DEFINED
+#define SkImagesSupport_DEFINED
+
+// This file contains functions that will use images -library if it is
+// present. If not, the functions will fail.
+
+#if SK_SUPPORT_GPU && defined(SK_DEVELOPER)
+class GrSurface;
+
+/** Save a GrSurface as PNG file.
+ * Returns false if save failed. */
+bool SkSaveGrSurfacePixelsAsPNG(GrSurface* surface, const char* filename);
+#endif
+
+#endif