Add unittests for the bugs found in previous CL.

third_party/WebKit/Source/platform/graphics/compositing/PaintArtifactCompositor.h

Index: third_party/WebKit/Source/platform/graphics/compositing/PaintArtifactCompositor.h
diff --git a/third_party/WebKit/Source/platform/graphics/compositing/PaintArtifactCompositor.h b/third_party/WebKit/Source/platform/graphics/compositing/PaintArtifactCompositor.h
index 6db04c5d4721d1ed13ed6ccaea26793a664541a6..8ba32a7dfe4e1b1c862e3d8423a84afa2b84c06c 100644
--- a/third_party/WebKit/Source/platform/graphics/compositing/PaintArtifactCompositor.h
+++ b/third_party/WebKit/Source/platform/graphics/compositing/PaintArtifactCompositor.h
@@ -170,6 +170,8 @@ class PLATFORM_EXPORT PaintArtifactCompositor {
   FRIEND_TEST_ALL_PREFIXES(PaintArtifactCompositorTestWithPropertyTrees,
                            Merge2DTransform);
   FRIEND_TEST_ALL_PREFIXES(PaintArtifactCompositorTestWithPropertyTrees,
+                           MergeTransformOrigin);
+  FRIEND_TEST_ALL_PREFIXES(PaintArtifactCompositorTestWithPropertyTrees,
                            MergeClip);
   FRIEND_TEST_ALL_PREFIXES(PaintArtifactCompositorTestWithPropertyTrees,
                            MergeOpacity);
@@ -188,6 +190,8 @@ class PLATFORM_EXPORT PaintArtifactCompositor {
   FRIEND_TEST_ALL_PREFIXES(PaintArtifactCompositorTestWithPropertyTrees,
                            TwoEffects);
   FRIEND_TEST_ALL_PREFIXES(PaintArtifactCompositorTestWithPropertyTrees,
+                           TwoTransformsClipBetween);
+  FRIEND_TEST_ALL_PREFIXES(PaintArtifactCompositorTestWithPropertyTrees,
                            OverlapTransform);
   FRIEND_TEST_ALL_PREFIXES(PaintArtifactCompositorTestWithPropertyTrees,
                            MightOverlap);
@@ -196,6 +200,8 @@ class PLATFORM_EXPORT PaintArtifactCompositor {
                            PendingLayer);
   FRIEND_TEST_ALL_PREFIXES(PaintArtifactCompositorTestWithPropertyTrees,
                            PendingLayerWithGeometry);
+  FRIEND_TEST_ALL_PREFIXES(PaintArtifactCompositorTestWithPropertyTrees,
+                           PendingLayerKnownOpaque);
 };
 
 }  // namespace blink