Fixup a bug about SVG text selection.

Source/core/layout/svg/LayoutSVGInlineText.cpp

Index: Source/core/layout/svg/LayoutSVGInlineText.cpp
diff --git a/Source/core/layout/svg/LayoutSVGInlineText.cpp b/Source/core/layout/svg/LayoutSVGInlineText.cpp
index 69553b53f7abf9be827f39d611b7d3ff8fb6bca5..dfdcd684c0f49037cac0fe7601916e084d382add 100644
--- a/Source/core/layout/svg/LayoutSVGInlineText.cpp
+++ b/Source/core/layout/svg/LayoutSVGInlineText.cpp
@@ -177,15 +177,22 @@ PositionWithAffinity LayoutSVGInlineText::positionForPoint(const LayoutPoint& po
         SVGInlineTextBox* textBox = toSVGInlineTextBox(box);
         Vector<SVGTextFragment>& fragments = textBox->textFragments();
 
-        unsigned textFragmentsSize = fragments.size();
+        unsigned textFragmentsSize = fragments.size(); 
         for (unsigned i = 0; i < textFragmentsSize; ++i) {
             const SVGTextFragment& fragment = fragments.at(i);
             FloatRect fragmentRect(fragment.x, fragment.y - baseline, fragment.width, fragment.height);
             fragment.buildFragmentTransform(fragmentTransform);
             fragmentRect = fragmentTransform.mapRect(fragmentRect);
+            // This is edge selection. If there is absolute-point between center and right edge of fragmentRect,
+            // selects rightEndge. In other cases selects left edge. 
+            FloatPoint selectedEdge;
+            if (absolutePoint.x() > fragmentRect.center().x() && absolutePoint.x() < fragmentRect.maxX()) {

[fs, 2015/04/23 16:29:51]

Why not just pick the closest edge? Using the left edge when the point is
outside to the right doesn't seem very good.

+                selectedEdge = fragmentRect.rightEdgeMidPoint();

[fs, 2015/04/23 16:29:51]

Rather than adding these new methods, you could do:

FloatPoint selectedEdge = fragmentRect.center();
...
selectedEdge.move(-fragmentRect.width() / 2, 0); // left edge
...
selectedEdge.move(fragmentRect.width() / 2, 0); // right edge

+            } else {
+                selectedEdge = fragmentRect.leftEdgeMidPoint();
+            }
 
-            float distance = powf(fragmentRect.x() - absolutePoint.x(), 2) +
-                powf(fragmentRect.y() + fragmentRect.height() / 2 - absolutePoint.y(), 2);
+            float distance = (selectedEdge - absolutePoint).diagonalLengthSquared();
 
             if (distance < closestDistance) {
                 closestDistance = distance;