Merge 125702 - [chromium] Must account for empty transformation lists when checking for big rotatio…

Source/WebCore/platform/graphics/chromium/AnimationTranslationUtil.cpp

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
  *     notice, this list of conditions and the following disclaimer in the
@@ skipping 135 matching lines @@
 }
 
 bool causesRotationOfAtLeast180Degrees(const TransformAnimationValue* value, const TransformAnimationValue* lastValue)
 {
     if (!lastValue)
         return false;
 
     const TransformOperations& operations = *value->value();
     const TransformOperations& lastOperations = *lastValue->value();
 
-    // We'll be doing matrix interpolation in this case. No risk of incorrect
-    // rotations here.
-    if (!operations.operationsMatch(lastOperations))
+    // We'll be doing matrix interpolation in this case. No risk of incorrect rotations here.
+    if (operations.size() && lastOperations.size() && !operations.operationsMatch(lastOperations))
         return false;
 
-    for (size_t i = 0; i < operations.size(); ++i) {
-        if (!isRotationType(operations.operations()[i]->getOperationType()))
-            continue;
+    size_t numOperations = max(operations.size(), lastOperations.size());
+    for (size_t i = 0; i < numOperations; ++i) {
+        float angle = 0;
+        if (i < operations.size()) {
+            if (!isRotationType(operations.operations()[i]->getOperationType()))
+                continue;
 
-        RotateTransformOperation* rotation = static_cast<RotateTransformOperation*>(operations.operations()[i].get());
-        RotateTransformOperation* lastRotation = static_cast<RotateTransformOperation*>(lastOperations.operations()[i].get());
+            RotateTransformOperation* rotation = static_cast<RotateTransformOperation*>(operations.operations()[i].get());
+            angle = rotation->angle();
+        }
 
-        if (fabs(rotation->angle() - lastRotation->angle()) >= 180)
+        float lastAngle = 0;
+        if (i < lastOperations.size()) {
+            if (!isRotationType(lastOperations.operations()[i]->getOperationType()))
+                continue;
+
+            RotateTransformOperation* lastRotation = static_cast<RotateTransformOperation*>(lastOperations.operations()[i].get());
+            lastAngle = lastRotation->angle();
+        }
+
+        if (fabs(angle - lastAngle) >= 180)
             return true;
     }
 
     return false;
 }
 
 template <>
 bool appendKeyframeWithStandardTimingFunction<TransformAnimationValue, WebTransformKeyframe, WebTransformAnimationCurve>(WebTransformAnimationCurve& curve, double keyTime, const TransformAnimationValue* value, const TransformAnimationValue* lastValue, WebKit::WebAnimationCurve::TimingFunctionType timingFunctionType, const FloatSize& boxSize)
 {
     if (causesRotationOfAtLeast180Degrees(value, lastValue))
@@ skipping 110 matching lines @@
     if (values.property() == AnimatedPropertyWebkitTransform)
         return createWebAnimation<TransformAnimationValue, WebTransformKeyframe, WebTransformAnimationCurve>(values, animation, animationId, groupId, timeOffset, WebKit::WebAnimation::TargetPropertyTransform, FloatSize(boxSize));
 
     if (values.property() == AnimatedPropertyOpacity)
         return createWebAnimation<FloatAnimationValue, WebFloatKeyframe, WebFloatAnimationCurve>(values, animation, animationId, groupId, timeOffset, WebKit::WebAnimation::TargetPropertyOpacity, FloatSize());
 
     return nullptr;
 }
 
 } // namespace WebCore