Fix blendToIdentity case in PerspectiveTransformOperation::blend

Source/platform/transforms/PerspectiveTransformOperation.cpp

Index: Source/platform/transforms/PerspectiveTransformOperation.cpp
diff --git a/Source/platform/transforms/PerspectiveTransformOperation.cpp b/Source/platform/transforms/PerspectiveTransformOperation.cpp
index 7c805c1d5efdb1a296c25fc61e334ed15aeea020..4630b609e16af59ff897add911007fbbf55f8d12 100644
--- a/Source/platform/transforms/PerspectiveTransformOperation.cpp
+++ b/Source/platform/transforms/PerspectiveTransformOperation.cpp
@@ -27,6 +27,7 @@
 #include "platform/transforms/PerspectiveTransformOperation.h"
 
 #include "platform/animation/AnimationUtilities.h"
+#include "platform/transforms/IdentityTransformOperation.h"
 #include "wtf/MathExtras.h"
 
 using namespace std;
@@ -39,7 +40,10 @@ PassRefPtr<TransformOperation> PerspectiveTransformOperation::blend(const Transf
         return this;
 
     if (blendToIdentity) {
-        double p = WebCore::blend(m_p, 1., progress); // FIXME: this seems wrong. https://bugs.webkit.org/show_bug.cgi?id=52700
+        if (progress == 1) {

[Julien - ping for review, 2014/01/10 13:41:41]

We don't put curly braces around single line if's.

+            return IdentityTransformOperation::create();
+        }
+        double p = m_p / (1 - progress);
         return PerspectiveTransformOperation::create(clampToPositiveInteger(p));
     }