Move overdraw tracking code from GraphicsContext to CanvasRenderingContext2D

Source/platform/graphics/GraphicsContextClient.cpp

Index: Source/platform/graphics/GraphicsContextClient.cpp
diff --git a/Source/platform/graphics/GraphicsContextClient.cpp b/Source/platform/graphics/GraphicsContextClient.cpp
deleted file mode 100644
index 630cad46b3c0da33241c5c34f01fd3d494bd0b61..0000000000000000000000000000000000000000
--- a/Source/platform/graphics/GraphicsContextClient.cpp
+++ /dev/null
@@ -1,122 +0,0 @@
-// Copyright 2015 The Chromium Authors. All rights reserved.
-//
-// The Chromium Authors can be found at
-// http://src.chromium.org/svn/trunk/src/AUTHORS
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//    * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//    * 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.
-//    * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND 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 THE COPYRIGHT
-// OWNER OR 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"
-#include "platform/graphics/GraphicsContextClient.h"
-
-#include "platform/graphics/GraphicsContext.h"
-#include "third_party/skia/include/core/SkCanvas.h"
-#include "third_party/skia/include/core/SkShader.h"
-
-namespace blink {
-
-void GraphicsContextClient::willDrawRect(GraphicsContext* context, const SkRect& rect, const SkPaint* paint, ImageType imageType, DrawType drawType)
-{
-    if (context->isDrawingToLayer())
-        return;
-
-    SkRect deviceRect;
-    if (drawType == UntransformedUnclippedFill) {
-        deviceRect = rect;
-    } else {
-        // FIXME: Early out if rotate/skew. To be thorough, we could compute
-        // an enclsed rect, but that would probably be overkill.
-        const SkMatrix& ctm = context->getTotalMatrix();
-        if (!ctm.rectStaysRect())
-            return;
-
-        if (context->hasComplexClip())
-            return;
-
-        ctm.mapRect(&deviceRect, rect);
-        SkIRect skIBounds;
-        if (!context->canvas()->getClipDeviceBounds(&skIBounds))
-            return;
-        SkRect skBounds = SkRect::Make(skIBounds);
-        if (!deviceRect.intersect(skBounds))
-            return;
-    }
-
-    const SkImageInfo& imageInfo = context->canvas()->imageInfo();
-    if (!deviceRect.contains(SkRect::MakeWH(imageInfo.width(), imageInfo.height())))
-        return;
-
-    bool isSourceOver = true;
-    unsigned alpha = 0xFF;
-    if (paint) {
-        if (drawType == FillOrStroke && paint->getStyle() == SkPaint::kStroke_Style)
-            return;
-        if (paint->getLooper() || paint->getImageFilter() || paint->getMaskFilter())
-            return;
-
-        SkXfermode* xfermode = paint->getXfermode();
-        if (xfermode) {
-            SkXfermode::Mode mode;
-            if (xfermode->asMode(&mode)) {
-                isSourceOver = mode == SkXfermode::kSrcOver_Mode;
-                if (!isSourceOver && mode != SkXfermode::kSrc_Mode && mode != SkXfermode::kClear_Mode)
-                    return; // The code below only knows how to handle Src, SrcOver, and Clear
-            } else {
-                // unknown xfermode
-                return;
-            }
-        }
-
-        if (isSourceOver) {
-            // With source over, we need to certify that alpha == 0xFF for all pixels
-            SkColorFilter* colorFilter = paint->getColorFilter();
-            if (colorFilter && !(colorFilter->getFlags() & SkColorFilter::kAlphaUnchanged_Flag))
-                return;
-
-            SkShader* shader = paint->getShader();
-            if (shader) {
-                // Shader overrides bitmap and paint color, so we can end here
-                if (shader->isOpaque())
-                    willOverwriteCanvas();
-                return;
-            }
-        }
-
-        alpha = paint->getAlpha();
-    }
-
-    if (isSourceOver) {
-        // With source over, we need to certify that alpha == 0xFF for all pixels
-        if (imageType == NonOpaqueImage)
-            return;
-        if (imageType == NoImage && alpha < 0xFF)
-            return;
-    }
-
-    willOverwriteCanvas();
-}
-
-} // blink