[Android] Allow custom ActionMode creation via ContentViewClient

ui/base/touch/selection_bound.cc

Index: ui/base/touch/selection_bound.cc
diff --git a/ui/base/touch/selection_bound.cc b/ui/base/touch/selection_bound.cc
index bd5b3c9c6beef999d944e58c6892cd446db8dbff..6aa472c6043ae38c2fda712dcab6197449542fdf 100644
--- a/ui/base/touch/selection_bound.cc
+++ b/ui/base/touch/selection_bound.cc
@@ -65,4 +65,20 @@ gfx::Rect RectBetweenSelectionBounds(const SelectionBound& b1,
   return gfx::Rect(top_left, gfx::Size(diff.x(), diff.y()));
 }
 
+gfx::RectF RectFBetweenSelectionBounds(const SelectionBound& b1,
+                                       const SelectionBound& b2) {
+  gfx::PointF top_left(b1.edge_top());

[jdduke (slow), 2015/04/14 18:39:12]

Note that we could implement RectBetweenSelectionBounds in terms of
RectFBetweenSelectionBounds, and we might also rename RectBetweenSelectionBounds
to RoundedRectBetweenSelectionBounds.

+  top_left.SetToMin(b1.edge_bottom());
+  top_left.SetToMin(b2.edge_top());
+  top_left.SetToMin(b2.edge_bottom());
+
+  gfx::PointF bottom_right(b1.edge_top());
+  bottom_right.SetToMax(b1.edge_bottom());
+  bottom_right.SetToMax(b2.edge_top());
+  bottom_right.SetToMax(b2.edge_bottom());
+
+  gfx::Vector2dF diff = bottom_right - top_left;
+  return gfx::RectF(top_left, gfx::SizeF(diff.x(), diff.y()));
+}
+
 }  // namespace ui