Avoid printing draw target info to stderr while running unit tests

Change draw target dump function to return a SkString. Clients can do
whatever they want with the string.

BUG=skia:1837
R=caryclark@google.com, bsalomon@google.com

Author: kkinnunen@nvidia.com

Review URL: https://codereview.chromium.org/72353003

git-svn-id: http://skia.googlecode.com/svn/trunk@12340 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/gpu/GrDrawTargetCaps.h b/src/gpu/GrDrawTargetCaps.h
index f6a6dc8..e597e09 100644
--- a/src/gpu/GrDrawTargetCaps.h
+++ b/src/gpu/GrDrawTargetCaps.h
@@ -5,13 +5,13 @@
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
-
-#include "SkRefCnt.h"
-#include "GrTypes.h"
-
 #ifndef GrDrawTargetCaps_DEFINED
 #define GrDrawTargetCaps_DEFINED
 
+#include "GrTypes.h"
+#include "SkRefCnt.h"
+#include "SkString.h"
+
 /**
  * Represents the draw target capabilities.
  */
@@ -24,7 +24,7 @@
     GrDrawTargetCaps& operator= (const GrDrawTargetCaps&);
 
     virtual void reset();
-    virtual void print() const;
+    virtual SkString dump() const;
 
     bool eightBitPaletteSupport() const { return f8BitPaletteSupport; }
     bool npotTextureTileSupport() const { return fNPOTTextureTileSupport; }