[WIP] Adding support for <iframe>s to slimming paint.

Source/core/paint/PartPainter.cpp

Index: Source/core/paint/PartPainter.cpp
diff --git a/Source/core/paint/PartPainter.cpp b/Source/core/paint/PartPainter.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..64bd69246c6f107004b7670c9a40ce265e9038ae
--- /dev/null
+++ b/Source/core/paint/PartPainter.cpp
@@ -0,0 +1,130 @@
+// Copyright 2014 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 "config.h"
+#include "core/paint/PartPainter.h"
+
+#include "core/frame/FrameView.h"
+#include "core/paint/BoxPainter.h"
+#include "core/paint/ClipRecorder.h"
+#include "core/paint/DrawingRecorder.h"
+#include "core/paint/TranslationRecorder.h"
+#include "core/paint/ViewDisplayList.h"
+#include "core/rendering/GraphicsContextAnnotator.h"
+#include "core/rendering/PaintInfo.h"
+#include "core/rendering/RenderLayer.h"
+#include "core/rendering/RenderPart.h"
+
+namespace blink {
+
+void PartPainter::paint(PaintInfo& paintInfo, const LayoutPoint& paintOffset)
+{
+    ANNOTATE_GRAPHICS_CONTEXT(paintInfo, &m_renderPart);
+
+    if (!m_renderPart.shouldPaint(paintInfo, paintOffset))
+        return;
+
+    LayoutPoint adjustedPaintOffset = paintOffset + m_renderPart.location();
+
+    LayoutRect bounds;
+    if (RuntimeEnabledFeatures::slimmingPaintEnabled()) {
+        bounds = m_renderPart.visualOverflowRect();
+        bounds.moveBy(paintOffset);
+    }
+
+    if (m_renderPart.hasBoxDecorationBackground() && (paintInfo.phase == PaintPhaseForeground || paintInfo.phase == PaintPhaseSelection)) {
+        DrawingRecorder recorder(paintInfo.context, &m_renderPart, paintInfo.phase, bounds);
+        m_renderPart.paintBoxDecorationBackground(paintInfo, adjustedPaintOffset);
+    }
+
+    if (paintInfo.phase == PaintPhaseMask) {
+        DrawingRecorder recorder(paintInfo.context, &m_renderPart, paintInfo.phase, bounds);
+        m_renderPart.paintMask(paintInfo, adjustedPaintOffset);
+        return;
+    }
+
+    if ((paintInfo.phase == PaintPhaseOutline || paintInfo.phase == PaintPhaseSelfOutline) && m_renderPart.style()->hasOutline()) {
+        DrawingRecorder recorder(paintInfo.context, &m_renderPart, paintInfo.phase, bounds);
+        m_renderPart.paintOutline(paintInfo, LayoutRect(adjustedPaintOffset, m_renderPart.size()));
+    }
+
+    if (paintInfo.phase != PaintPhaseForeground)
+        return;
+
+    OwnPtr<ClipRecorder> clipRecorder;
+    if (m_renderPart.style()->hasBorderRadius()) {
+        LayoutRect borderRect = LayoutRect(adjustedPaintOffset, m_renderPart.size());
+        if (borderRect.isEmpty())
+            return;
+
+        RoundedRect roundedInnerRect = m_renderPart.style()->getRoundedInnerBorderFor(borderRect,
+            m_renderPart.paddingTop() + m_renderPart.borderTop(),
+            m_renderPart.paddingBottom() + m_renderPart.borderBottom(),
+            m_renderPart.paddingLeft() + m_renderPart.borderLeft(),
+            m_renderPart.paddingRight() + m_renderPart.borderRight(), true, true);
+
+        // FIXME: Need a proper identifier (layer and phase pair) for this clip item.
+        clipRecorder = adoptPtr(new ClipRecorder(m_renderPart.layer(), paintInfo.context, DisplayItem::ClipLayerFragmentForeground, borderRect));
+        // FIXME: Copied from BoxPainter::clipRoundedInnerRect. Should make it work with ClipRecorder.
+        if (roundedInnerRect.isRenderable()) {
+            clipRecorder->addRoundedRectClip(roundedInnerRect);
+        } else {
+            if (!roundedInnerRect.radii().topLeft().isEmpty() || !roundedInnerRect.radii().bottomRight().isEmpty()) {
+                IntRect topCorner(roundedInnerRect.rect().x(), roundedInnerRect.rect().y(), borderRect.maxX() - roundedInnerRect.rect().x(), borderRect.maxY() - roundedInnerRect.rect().y());
+                RoundedRect::Radii topCornerRadii;
+                topCornerRadii.setTopLeft(roundedInnerRect.radii().topLeft());
+                clipRecorder->addRoundedRectClip(RoundedRect(topCorner, topCornerRadii));
+
+                IntRect bottomCorner(borderRect.x(), borderRect.y(), roundedInnerRect.rect().maxX() - borderRect.x(), roundedInnerRect.rect().maxY() - borderRect.y());
+                RoundedRect::Radii bottomCornerRadii;
+                bottomCornerRadii.setBottomRight(roundedInnerRect.radii().bottomRight());
+                clipRecorder->addRoundedRectClip(RoundedRect(bottomCorner, bottomCornerRadii));
+            }
+
+            if (!roundedInnerRect.radii().topRight().isEmpty() || !roundedInnerRect.radii().bottomLeft().isEmpty()) {
+                IntRect topCorner(borderRect.x(), roundedInnerRect.rect().y(), roundedInnerRect.rect().maxX() - borderRect.x(), borderRect.maxY() - roundedInnerRect.rect().y());
+                RoundedRect::Radii topCornerRadii;
+                topCornerRadii.setTopRight(roundedInnerRect.radii().topRight());
+                clipRecorder->addRoundedRectClip(RoundedRect(topCorner, topCornerRadii));
+
+                IntRect bottomCorner(roundedInnerRect.rect().x(), borderRect.y(), borderRect.maxX() - roundedInnerRect.rect().x(), roundedInnerRect.rect().maxY() - borderRect.y());
+                RoundedRect::Radii bottomCornerRadii;
+                bottomCornerRadii.setBottomLeft(roundedInnerRect.radii().bottomLeft());
+                clipRecorder->addRoundedRectClip(RoundedRect(bottomCorner, bottomCornerRadii));
+            }
+        }
+    }
+
+    paintContents(paintInfo, paintOffset);
+
+    clipRecorder.clear();
+
+    DrawingRecorder recorder(paintInfo.context, &m_renderPart, paintInfo.phase, bounds);
+    // Paint a partially transparent wash over selected widgets.
+    if (m_renderPart.isSelected() && !m_renderPart.document().printing()) {
+        LayoutRect rect = m_renderPart.localSelectionRect();
+        rect.moveBy(adjustedPaintOffset);
+        paintInfo.context->fillRect(pixelSnappedIntRect(rect), m_renderPart.selectionBackgroundColor());
+    }
+
+    if (m_renderPart.canResize())
+        m_renderPart.layer()->scrollableArea()->paintResizer(paintInfo.context, roundedIntPoint(adjustedPaintOffset), paintInfo.rect);
+}
+
+void PartPainter::paintContents(PaintInfo& paintInfo, const LayoutPoint& paintOffset)
+{
+    if (!m_renderPart.widget())
+        return;
+    Widget* widget = m_renderPart.widget();
+
+    LayoutPoint adjustedPaintOffset = paintOffset + m_renderPart.location() + m_renderPart.contentBoxRect().location();
+    IntSize widgetPaintOffset = roundedIntPoint(adjustedPaintOffset) - widget->frameRect().location();
+
+    TranslationRecorder translationRecorder(&m_renderPart, paintInfo.context, widgetPaintOffset);
+    IntRect paintRect = paintInfo.rect;
+    paintRect.move(-widgetPaintOffset);
+    widget->paint(paintInfo.context, paintRect);
+}
+
+} // namespace blink