Fix image map focus ring painting

third_party/WebKit/Source/core/html/HTMLAreaElement.cpp

Index: third_party/WebKit/Source/core/html/HTMLAreaElement.cpp
diff --git a/third_party/WebKit/Source/core/html/HTMLAreaElement.cpp b/third_party/WebKit/Source/core/html/HTMLAreaElement.cpp
index 11ffd7311a31beb671927a78a697d29056062b88..b89b0bd6d7244e42235cec90ae1bf610c129ab54 100644
--- a/third_party/WebKit/Source/core/html/HTMLAreaElement.cpp
+++ b/third_party/WebKit/Source/core/html/HTMLAreaElement.cpp
@@ -48,7 +48,6 @@ using namespace HTMLNames;
 
 inline HTMLAreaElement::HTMLAreaElement(Document& document)
     : HTMLAnchorElement(areaTag, document)
-    , m_lastSize(-1, -1)
     , m_shape(Rect)
 {
 }
@@ -78,10 +77,10 @@ void HTMLAreaElement::parseAttribute(const QualifiedName& name, const AtomicStri
             // 'shape' attribute is 'rect'.
             m_shape = Rect;
         }
-        invalidateCachedRegion();
+        invalidateCachedPath();
     } else if (name == coordsAttr) {
         m_coords = parseHTMLListOfFloatingPointNumbers(value.getString());
-        invalidateCachedRegion();
+        invalidateCachedPath();
     } else if (name == altAttr || name == accesskeyAttr) {
         // Do nothing.
     } else {
@@ -89,36 +88,26 @@ void HTMLAreaElement::parseAttribute(const QualifiedName& name, const AtomicStri
     }
 }
 
-void HTMLAreaElement::invalidateCachedRegion()
+void HTMLAreaElement::invalidateCachedPath()
 {
-    m_lastSize = LayoutSize(-1, -1);
+    m_path = nullptr;
 }
 
-bool HTMLAreaElement::pointInArea(LayoutPoint location, const LayoutSize& containerSize)
+bool HTMLAreaElement::pointInArea(const LayoutPoint& location, const LayoutObject* containerObject) const
 {
-    if (m_lastSize != containerSize) {
-        m_region = adoptPtr(new Path(getRegion(containerSize)));
-        m_lastSize = containerSize;
-    }
-
-    return m_region->contains(FloatPoint(location));
+    return getPath(containerObject).contains(FloatPoint(location));
 }
 
-Path HTMLAreaElement::computePath(const LayoutObject* obj) const
+LayoutRect HTMLAreaElement::computeAbsoluteRect(const LayoutObject* containerObject) const
 {
-    if (!obj)
-        return Path();
+    if (!containerObject)
+        return LayoutRect();
 
     // FIXME: This doesn't work correctly with transforms.
-    FloatPoint absPos = obj->localToAbsolute();
+    FloatPoint absPos = containerObject->localToAbsolute();
 
-    // Default should default to the size of the containing object.
-    LayoutSize size = m_lastSize;
-    if (m_shape == Default)
-        size = obj->absoluteClippedOverflowRect().size();
-
-    Path p = getRegion(size);
-    float zoomFactor = obj->style()->effectiveZoom();
+    Path p = getPath(containerObject);

[pdr., 2016/04/26 01:29:35]

Nit: p -> path

+    float zoomFactor = containerObject->style()->effectiveZoom();
     if (zoomFactor != 1.0f) {

[pdr., 2016/04/26 01:29:35]

Do we really want to zoom this value? I traced the callers of
computeAbsoluteRect and they don't seem to apply zoom elsewhere.

         AffineTransform zoomTransform;
         zoomTransform.scale(zoomFactor);
@@ -126,35 +115,43 @@ Path HTMLAreaElement::computePath(const LayoutObject* obj) const
     }
 
     p.translate(toFloatSize(absPos));
-    return p;
+    return enclosingLayoutRect(p.boundingRect());
 }
 
-LayoutRect HTMLAreaElement::computeRect(const LayoutObject* obj) const
+Path HTMLAreaElement::getPath(const LayoutObject* containerObject) const
 {
-    return enclosingLayoutRect(computePath(obj).boundingRect());
-}
+    // Always recompute for default shape because it depends on container object's size
+    // and is cheap.
+    if (m_shape == Default) {
+        Path path;

[pdr., 2016/04/26 01:29:35]

Invalidate m_path for this codepath?

[Xianzhu, 2016/04/26 17:42:27]

Done.

+        if (containerObject && containerObject->isBox())
+            path.addRect(FloatRect(toLayoutBox(containerObject)->borderBoxRect()));
+        return path;
+    }
+
+    if (m_path)
+        return *m_path;
+
+    m_path = adoptPtr(new Path);
 
-Path HTMLAreaElement::getRegion(const LayoutSize& size) const
-{
     if (m_coords.isEmpty() && m_shape != Default)

[pdr., 2016/04/26 01:29:35]

m_shape can't be Default here so this can just be:
if (m_coords.isEmpty())
    return *m_path;

[Xianzhu, 2016/04/26 17:42:27]

Done.

-        return Path();
+        return *m_path;
 
-    Path path;
     switch (m_shape) {
     case Poly:
         if (m_coords.size() >= 6) {
             int numPoints = m_coords.size() / 2;
-            path.moveTo(FloatPoint(clampCoordinate(m_coords[0]), clampCoordinate(m_coords[1])));
+            m_path->moveTo(FloatPoint(clampCoordinate(m_coords[0]), clampCoordinate(m_coords[1])));
             for (int i = 1; i < numPoints; ++i)
-                path.addLineTo(FloatPoint(clampCoordinate(m_coords[i * 2]), clampCoordinate(m_coords[i * 2 + 1])));
-            path.closeSubpath();
-            path.setWindRule(RULE_EVENODD);
+                m_path->addLineTo(FloatPoint(clampCoordinate(m_coords[i * 2]), clampCoordinate(m_coords[i * 2 + 1])));
+            m_path->closeSubpath();
+            m_path->setWindRule(RULE_EVENODD);
         }
         break;
     case Circle:
         if (m_coords.size() >= 3 && m_coords[2] > 0) {
             float r = clampCoordinate(m_coords[2]);
-            path.addEllipse(FloatRect(clampCoordinate(m_coords[0]) - r, clampCoordinate(m_coords[1]) - r, 2 * r, 2 * r));
+            m_path->addEllipse(FloatRect(clampCoordinate(m_coords[0]) - r, clampCoordinate(m_coords[1]) - r, 2 * r, 2 * r));
         }
         break;
     case Rect:
@@ -163,15 +160,15 @@ Path HTMLAreaElement::getRegion(const LayoutSize& size) const
             float y0 = clampCoordinate(m_coords[1]);
             float x1 = clampCoordinate(m_coords[2]);
             float y1 = clampCoordinate(m_coords[3]);
-            path.addRect(FloatRect(x0, y0, x1 - x0, y1 - y0));
+            m_path->addRect(FloatRect(x0, y0, x1 - x0, y1 - y0));
         }
         break;
-    case Default:
-        path.addRect(FloatRect(FloatPoint(0, 0), FloatSize(size)));
+    default:
+        ASSERT_NOT_REACHED();
         break;
     }
 
-    return path;
+    return *m_path;
 }
 
 HTMLImageElement* HTMLAreaElement::imageElement() const