add const to encodePixels pixel parameter

tests/PictureTest.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBBoxHierarchy.h"
 #include "SkBlurImageFilter.h"
 #include "SkCanvas.h"
@@ skipping 1430 matching lines @@
     SkCanvas canvas;
     canvas.drawPicture(picture);
 }
 #endif
 
 // Encodes to PNG, unless there is already encoded data, in which case that gets
 // used.
 // FIXME: Share with PictureRenderer.cpp?
 class PngPixelSerializer : public SkPixelSerializer {
 public:
-    virtual bool onUseEncodedData(const void*, size_t) SK_OVERRIDE { return true; }
-    virtual SkData* onEncodePixels(const SkImageInfo& info, void* pixels,
-                                   size_t rowBytes) SK_OVERRIDE {
-        SkBitmap bm;
-        if (!bm.installPixels(info, pixels, rowBytes)) {
-            return NULL;
-        }
-        return SkImageEncoder::EncodeData(bm, SkImageEncoder::kPNG_Type, 100);
+    bool onUseEncodedData(const void*, size_t) SK_OVERRIDE { return true; }
+    SkData* onEncodePixels(const SkImageInfo& info, const void* pixels,
+                           size_t rowBytes) SK_OVERRIDE {
+        return SkImageEncoder::EncodeData(info, pixels, rowBytes, SkImageEncoder::kPNG_Type, 100);
     }
 };
 
 static SkData* serialized_picture_from_bitmap(const SkBitmap& bitmap) {
     SkPictureRecorder recorder;
     SkCanvas* canvas = recorder.beginRecording(SkIntToScalar(bitmap.width()),
                                                SkIntToScalar(bitmap.height()));
     canvas->drawBitmap(bitmap, 0, 0);
     SkAutoTUnref<SkPicture> picture(recorder.endRecording());
 
@@ skipping 463 matching lines @@
 
     // The picture shares the immutable pixels but copies the mutable ones.
     REPORTER_ASSERT(r, mut.pixelRef()->unique());
     REPORTER_ASSERT(r, !immut.pixelRef()->unique());
 
     // When the picture goes away, it's just our bitmaps holding the refs.
     pic.reset(NULL);
     REPORTER_ASSERT(r, mut.pixelRef()->unique());
     REPORTER_ASSERT(r, immut.pixelRef()->unique());
 }