Add machinery for dumping SkPictures to disk

R=ianh@google.com

Review URL: https://codereview.chromium.org/1235813005 .

shell/BUILD.gn

@@ -32,6 +32,8 @@ source_set("common") {
     "gpu/ganesh_context.h",
     "gpu/ganesh_surface.cc",
     "gpu/ganesh_surface.h",
+    "gpu/picture_serializer.cc",
+    "gpu/picture_serializer.h",
     "gpu/rasterizer.cc",
     "gpu/rasterizer.h",
     "gpu_delegate.cc",

shell/gpu/picture_serializer.cc

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "sky/shell/gpu/picture_serializer.h"
+
+#include "third_party/skia/include/core/SkData.h"
+#include "third_party/skia/include/core/SkPixelSerializer.h"
+#include "third_party/skia/include/core/SkStream.h"
+#include "ui/gfx/codec/png_codec.h"
+
+namespace sky {
+
+class PngPixelSerializer : public SkPixelSerializer {
+ public:
+  bool onUseEncodedData(const void*, size_t) override { return true; }
+  SkData* onEncodePixels(const SkImageInfo& info, const void* pixels,
+      size_t row_bytes) override {
+    std::vector<unsigned char> data;
+
+    SkBitmap bm;
+    if (!bm.installPixels(info, const_cast<void*>(pixels), row_bytes))
+      return nullptr;
+    if (!gfx::PNGCodec::EncodeBGRASkBitmap(bm, false, &data))
+      return nullptr;
+    return SkData::NewWithCopy(&data.front(), data.size());
+  }
+};
+
+void SerializePicture(const char* file_name, SkPicture* picture) {
+  SkFILEWStream stream(file_name);
+  PngPixelSerializer serializer;
+  picture->serialize(&stream, &serializer);
+}
+
+}  // namespace sky

shell/gpu/picture_serializer.h

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef SKY_SHELL_GPU_PICTURE_SERIALIZER_H_
+#define SKY_SHELL_GPU_PICTURE_SERIALIZER_H_
+
+#include "third_party/skia/include/core/SkPicture.h"
+
+namespace sky {
+
+void SerializePicture(const char* file_name, SkPicture*);
+
+}  // namespace sky
+
+#endif  // SKY_SHELL_GPU_PICTURE_SERIALIZER_H_

shell/gpu/rasterizer.cc

@@ -7,6 +7,7 @@
 #include "base/trace_event/trace_event.h"
 #include "sky/shell/gpu/ganesh_context.h"
 #include "sky/shell/gpu/ganesh_surface.h"
+#include "sky/shell/gpu/picture_serializer.h"
 #include "third_party/skia/include/core/SkCanvas.h"
 #include "third_party/skia/include/core/SkPicture.h"
 #include "ui/gl/gl_bindings.h"
@@ -58,6 +59,8 @@ void Rasterizer::Draw(skia::RefPtr<SkPicture> picture) {
 
   DrawPicture(picture.get());
   surface_->SwapBuffers();
+
+  // SerializePicture("/data/data/org.domokit.sky.demo/cache/layer0.skp", picture.get());
 }
 
 void Rasterizer::DrawPicture(SkPicture* picture) {