Initial import attempt, just to play with. Many things disabled/removed

ui/cc/CanvasLayerTextureUpdater.cpp

Index: ui/cc/CanvasLayerTextureUpdater.cpp
diff --git a/ui/cc/CanvasLayerTextureUpdater.cpp b/ui/cc/CanvasLayerTextureUpdater.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..46f7bec37ab3cd5d873eb2b7973cff2dec0104aa
--- /dev/null
+++ b/ui/cc/CanvasLayerTextureUpdater.cpp
@@ -0,0 +1,89 @@
+/*
+ * Copyright (C) 2011 Google Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1.  Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ * 2.  Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+
+#include "config.h"
+
+#if USE(ACCELERATED_COMPOSITING)
+
+#include "CanvasLayerTextureUpdater.h"
+
+#include "FloatRect.h"
+#include "IntRect.h"
+#include "LayerPainterChromium.h"
+#include "SkCanvas.h"
+#include "SkPaint.h"
+#include "SkRect.h"
+#include "TraceEvent.h"
+
+namespace WebCore {
+
+CanvasLayerTextureUpdater::CanvasLayerTextureUpdater(PassOwnPtr<LayerPainterChromium> painter)
+    : m_painter(painter)
+{
+}
+
+CanvasLayerTextureUpdater::~CanvasLayerTextureUpdater()
+{
+}
+
+// Skia has problems when passed infinite, etc floats, filter them to 0.
+inline SkScalar WebCoreFloatToSkScalar(float f)
+{
+    return SkFloatToScalar(isfinite(f) ? f : 0);
+}
+
+
+void CanvasLayerTextureUpdater::paintContents(SkCanvas* canvas, const IntRect& contentRect, float contentsScale, IntRect& resultingOpaqueRect)
+{
+    TRACE_EVENT0("cc", "CanvasLayerTextureUpdater::paintContents");
+    canvas->save();
+    canvas->translate(WebCoreFloatToSkScalar(-contentRect.x()), WebCoreFloatToSkScalar(-contentRect.y()));
+
+    IntRect scaledContentRect = contentRect;
+
+    if (contentsScale != 1.0) {
+        canvas->scale(WebCoreFloatToSkScalar(contentsScale), WebCoreFloatToSkScalar(contentsScale));
+
+        FloatRect rect = contentRect;
+        rect.scale(1 / contentsScale);
+        scaledContentRect = enclosingIntRect(rect);
+    }
+
+    SkPaint paint;
+    paint.setAntiAlias(false);
+    paint.setXfermodeMode(SkXfermode::kClear_Mode);
+    SkRect skScaledContentRect = SkRect::MakeXYWH(scaledContentRect.x(), scaledContentRect.y(), scaledContentRect.width(), scaledContentRect.height());
+    canvas->drawRect(skScaledContentRect, paint);
+    canvas->clipRect(skScaledContentRect);
+
+    m_painter->paint(canvas, scaledContentRect, resultingOpaqueRect);
+    canvas->restore();
+
+    m_contentRect = contentRect;
+}
+
+} // namespace WebCore
+#endif // USE(ACCELERATED_COMPOSITING)