Animations: Fix blend to identity for transform: translate Z

third_party/WebKit/LayoutTests/animations/interpolation/transform-interpolation.html

Index: third_party/WebKit/LayoutTests/animations/interpolation/transform-interpolation.html
diff --git a/third_party/WebKit/LayoutTests/animations/interpolation/transform-interpolation.html b/third_party/WebKit/LayoutTests/animations/interpolation/transform-interpolation.html
index 318436a3e7d8c5184e289c4ac8424b15572b27c7..3e9960f798b8399980d85052c08d7b02aada78a7 100644
--- a/third_party/WebKit/LayoutTests/animations/interpolation/transform-interpolation.html
+++ b/third_party/WebKit/LayoutTests/animations/interpolation/transform-interpolation.html
@@ -589,6 +589,18 @@ assertInterpolation({
   {at: 1, is: 'matrix3d(1, 0, 0, 0, -4.370079726523038, 2, 0, 0, 0, 0, 1, 0, 4, -12, 8, 1)'},
   {at: 2, is: 'matrix3d(1, 0, 0, 0, -17.782462353533823, 3, 0, 0, 0.021237113402061854, -0.010618556701030927, 1.03, 0.0026546391752577322, 0, -20, 4, 0.9793814432989691)'},
 ]);
+assertInterpolation({
+  property: 'transform',
+  from: 'translate3D(100px, 200px, 300px)',
+  to: 'none'
+}, [
+  {at: -1, is: 'matrix3d(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 200, 400, 600, 1)'},
+  {at: 0, is: 'matrix3d(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 100, 200, 300, 1)'},
+  {at: 0.25, is: 'matrix3d(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 75, 150, 225, 1)'},
+  {at: 0.75, is: 'matrix3d(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 25, 50, 75, 1)'},
+  {at: 1, is: 'matrix(1, 0, 0, 1, 0, 0) '},
+  {at: 2, is: 'matrix3d(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, -100, -200, -300, 1)'},
+]);
 
 // Matrix
 assertInterpolation({