Add Skia benchmarking extension.

This extension is intended to expose some of the Skia debugger backend
functionality to JS. Enabled at runtime by --enable-skia-benchmarking
(disabled by default).

Currently, only the rasterize() method is implemented:

rasterize: function(base64Picture) {
    return { width, height, RGBA8 ArrayBuffer};
}

R=nduca@chromium.org,pdr@chromium.org
BUG=240465

Review URL: https://chromiumcodereview.appspot.com/14698011

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@199963 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 102 insertions, 0 deletions

diff --git a/content/renderer/skia_benchmarking_extension.cc b/content/renderer/skia_benchmarking_extension.cc
new file mode 100644
index 0000000..7adb77d
--- /dev/null
+++ b/content/renderer/skia_benchmarking_extension.cc
@@ -0,0 +1,102 @@
+// Copyright (c) 2013 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 "content/renderer/skia_benchmarking_extension.h"
+
+#include "cc/resources/picture.h"
+#include "third_party/WebKit/Source/WebKit/chromium/public/WebArrayBuffer.h"
+#include "third_party/skia/include/core/SkCanvas.h"
+#include "third_party/skia/include/core/SkGraphics.h"
+#include "v8/include/v8.h"
+
+namespace {
+
+const char kSkiaBenchmarkingExtensionName[] = "v8/SkiaBenchmarking";
+
+class SkiaBenchmarkingWrapper : public v8::Extension {
+ public:
+  SkiaBenchmarkingWrapper() :
+      v8::Extension(kSkiaBenchmarkingExtensionName,
+        "if (typeof(chrome) == 'undefined') {"
+        "  chrome = {};"
+        "};"
+        "if (typeof(chrome.skiaBenchmarking) == 'undefined') {"
+        "  chrome.skiaBenchmarking = {};"
+        "};"
+        "chrome.skiaBenchmarking.rasterize = function(picture) {"
+        "  /* "
+        "     Rasterizes a base64-encoded Picture."
+        "     @param {String} picture Base64-encoded Picture. "
+        "     @returns { 'width': {Number}, 'height': {Number},"
+        "                'data': {ArrayBuffer} }"
+        "   */"
+        "  native function Rasterize();"
+        "  return Rasterize(picture);"
+        "};"
+        ) {
+      content::SkiaBenchmarkingExtension::InitSkGraphics();
+  }
+
+  virtual v8::Handle<v8::FunctionTemplate> GetNativeFunction(
+      v8::Handle<v8::String> name) OVERRIDE {
+    if (name->Equals(v8::String::New("Rasterize")))
+      return v8::FunctionTemplate::New(Rasterize);
+
+    return v8::Handle<v8::FunctionTemplate>();
+  }
+
+  static v8::Handle<v8::Value> Rasterize(const v8::Arguments& args) {
+    if (args.Length() != 1)
+      return v8::Undefined();
+
+    v8::String::AsciiValue base64_picture(args[0]);
+    scoped_refptr<cc::Picture> picture =
+        cc::Picture::CreateFromBase64String(*base64_picture);
+    if (!picture)
+      return v8::Undefined();
+
+    gfx::Rect rect = picture->LayerRect();
+    SkBitmap bitmap;
+    bitmap.setConfig(SkBitmap::kARGB_8888_Config, rect.width(), rect.height());
+    if (!bitmap.allocPixels())
+      return v8::Undefined();
+
+    bitmap.eraseARGB(0, 0, 0, 0);
+    SkCanvas canvas(bitmap);
+    picture->Raster(&canvas, rect, 1, true);
+
+    WebKit::WebArrayBuffer buffer =
+        WebKit::WebArrayBuffer::create(bitmap.getSize(), 1);
+    memcpy(buffer.data(), bitmap.getPixels(), bitmap.getSize());
+
+    v8::Handle<v8::Object> result = v8::Object::New();
+    result->Set(v8::String::New("width"), v8::Number::New(rect.width()));
+    result->Set(v8::String::New("height"), v8::Number::New(rect.height()));
+    result->Set(v8::String::New("data"), buffer.toV8Value());
+
+    return result;
+  }
+};
+
+} // namespace
+
+namespace content {
+
+v8::Extension* SkiaBenchmarkingExtension::Get() {
+  return new SkiaBenchmarkingWrapper();
+}
+
+void SkiaBenchmarkingExtension::InitSkGraphics() {
+    // Always call on the main render thread.
+    // Does not need to be thread-safe, as long as the above holds.
+    // FIXME: remove this after Skia updates SkGraphics::Init() to be
+    //        thread-safe and idempotent.
+    static bool skia_initialized = false;
+    if (!skia_initialized) {
+      SkGraphics::Init();
+      skia_initialized = true;
+    }
+}
+
+} // namespace content