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

cc/layer_tree_host_impl.cc

Index: cc/layer_tree_host_impl.cc
diff --git a/cc/layer_tree_host_impl.cc b/cc/layer_tree_host_impl.cc
index 740c361935199ca9b78617a1adece1e59db96d12..19f6406f011374b5aabbacbd640eb85198587706 100644
--- a/cc/layer_tree_host_impl.cc
+++ b/cc/layer_tree_host_impl.cc
@@ -498,7 +498,8 @@ static void appendQuadsToFillScreen(RenderPass* targetRenderPass, LayerImpl* roo
                             opacity);
 
     AppendQuadsData appendQuadsData;
-    gfx::Transform transformToLayerSpace = MathUtil::inverse(rootLayer->screenSpaceTransform());
+    gfx::Transform transformToLayerSpace(gfx::Transform::kSkipInitialization);
+    rootLayer->screenSpaceTransform().GetInverse(&transformToLayerSpace);

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

You can DCHECK the return value here instead of IsInvertible() up above.

     for (Region::Iterator fillRects(fillRegion); fillRects.has_rect(); fillRects.next()) {
         // The root layer transform is composed of translations and scales only,
         // no perspective, so mapping is sufficient.
@@ -1308,7 +1309,8 @@ static gfx::Vector2dF scrollLayerWithViewportSpaceDelta(PinchZoomViewport* viewp
     // Layers with non-invertible screen space transforms should not have passed the scroll hit
     // test in the first place.
     DCHECK(layerImpl.screenSpaceTransform().IsInvertible());
-    gfx::Transform inverseScreenSpaceTransform = MathUtil::inverse(layerImpl.screenSpaceTransform());
+    gfx::Transform inverseScreenSpaceTransform(gfx::Transform::kSkipInitialization);
+    layerImpl.screenSpaceTransform().GetInverse(&inverseScreenSpaceTransform);

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

Can DCHECK here instead of IsInvertible also.

 
     gfx::PointF screenSpacePoint = gfx::ScalePoint(viewportPoint, scaleFromViewportToScreenSpace);