Migrate from MathUtil::inverse() to gfx::Transform::GetInverse()

cc/layer_tree_host.cc

Index: cc/layer_tree_host.cc
diff --git a/cc/layer_tree_host.cc b/cc/layer_tree_host.cc
index 70e1620b670b04e03428c630f7722c6842839b21..e4c23a2124f09cacac4a8c35e6581feb300c67a0 100644
--- a/cc/layer_tree_host.cc
+++ b/cc/layer_tree_host.cc
@@ -757,7 +757,8 @@ gfx::PointF LayerTreeHost::adjustEventPointForPinchZoom(const gfx::PointF& zoome
 
     // Scale to screen space before applying implTransform inverse.
     gfx::PointF zoomedScreenspacePoint = gfx::ScalePoint(zoomedViewportPoint, deviceScaleFactor());
-    gfx::Transform inverseImplTransform = MathUtil::inverse(m_implTransform);
+    gfx::Transform inverseImplTransform(gfx::Transform::kSkipInitialization);
+    m_implTransform.GetInverse(&inverseImplTransform);

[danakj, 2012/12/19 05:23:06]

You could DCHECK the result of GetInverse() here to save an IsInvertible().

 
     bool wasClipped = false;
     gfx::PointF unzoomedScreenspacePoint = MathUtil::projectPoint(inverseImplTransform, zoomedScreenspacePoint, wasClipped);