Apply bleed-avoidance insets _after_ constraining the border

Source/platform/geometry/FloatRoundedRect.cpp

Index: Source/platform/geometry/FloatRoundedRect.cpp
diff --git a/Source/platform/geometry/FloatRoundedRect.cpp b/Source/platform/geometry/FloatRoundedRect.cpp
index 8875445361c7e0320d13003495e753fbd073c231..b2f7db8651f5a71d0efca596460a391c5baf9758 100644
--- a/Source/platform/geometry/FloatRoundedRect.cpp
+++ b/Source/platform/geometry/FloatRoundedRect.cpp
@@ -215,6 +215,12 @@ void FloatRoundedRect::inflateWithRadii(int size)
     m_radii.scale(factor);
 }
 
+void FloatRoundedRect::shrink(const FloatRectOutsets& insets)
+{
+    m_rect.expand(insets);
+    m_radii.shrink(-insets.top(), -insets.bottom(), -insets.left(), -insets.right());

[f(malita), 2015/05/11 18:09:14]

Nit: I find the difference in Radii::shrink() vs. Radii::expand() semantics
super annoying. It's not immediately obvious what's going on here (rect expand
vs. radii shrink vs. sign(insets)), so maybe we should avoid adding this
FloatRoundedRect API. Can we adjust the rect/radii explicitly in
backgroundRoundedRectAdjustedForBleedAvoidance() and just use a new
FloatRoundedRect instead?

[fs, 2015/05/12 08:53:55]

Annoying indeed...
I'd semi-planed a follow-up which used it in yet another place - mutating a
FloatRoundedRect is kind of tedious...

I was hoping we could eventually get a structure like:

<compute (outer) border>
<determine inset>
<apply inset (if needed)>

I'm a bit stumped by the BackgroundOverBorder case though (since it doesn't
factor in continuation effects.)

+}
+
 bool FloatRoundedRect::intersectsQuad(const FloatQuad& quad) const
 {
     if (!quad.intersectsRect(m_rect))