Fix common axes logic to detect negated axes as not common

third_party/WebKit/Source/platform/transforms/Rotation.cpp

Index: third_party/WebKit/Source/platform/transforms/Rotation.cpp
diff --git a/third_party/WebKit/Source/platform/transforms/Rotation.cpp b/third_party/WebKit/Source/platform/transforms/Rotation.cpp
index 15d08ba7ed5c423bceec1cfef784248999f48239..6b762956978256b9355a3789174a3ed259346be3 100644
--- a/third_party/WebKit/Source/platform/transforms/Rotation.cpp
+++ b/third_party/WebKit/Source/platform/transforms/Rotation.cpp
@@ -82,9 +82,12 @@ bool Rotation::getCommonAxis(const Rotation& a,
     return true;
   }
 
+  double dot = a.axis.dot(b.axis);
+  if (dot < 0)
+    return false;
+
   double aSquared = a.axis.lengthSquared();
   double bSquared = b.axis.lengthSquared();
-  double dot = a.axis.dot(b.axis);
   double error = std::abs(1 - (dot * dot) / (aSquared * bSquared));
   if (error > kAngleEpsilon)
     return false;