Add platform/transforms pretty printers for logging and testing

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

Index: third_party/WebKit/Source/platform/transforms/AffineTransform.cpp
diff --git a/third_party/WebKit/Source/platform/transforms/AffineTransform.cpp b/third_party/WebKit/Source/platform/transforms/AffineTransform.cpp
index 3f08a99d8293c271b4edd0f4c4b327cbfcf434be..690c74a282e8ef0ef64e7b5e9788e3dedf44538d 100644
--- a/third_party/WebKit/Source/platform/transforms/AffineTransform.cpp
+++ b/third_party/WebKit/Source/platform/transforms/AffineTransform.cpp
@@ -32,6 +32,7 @@
 #include "platform/geometry/FloatRect.h"
 #include "platform/geometry/IntRect.h"
 #include "wtf/MathExtras.h"
+#include "wtf/text/WTFString.h"
 
 namespace blink {
 
@@ -400,4 +401,34 @@ void AffineTransform::recompose(const DecomposedType& decomp)
     this->scale(decomp.scaleX, decomp.scaleY);
 }
 
+String AffineTransform::toString(bool asMatrix) const
+{
+    if (asMatrix) {
+        // Return as a matrix in row-major order.
+        return String::format("[%lg,%lg,%lg,\n%lg,%lg,%lg]",
+            a(), c(), e(),
+            b(), d(), f());
+    }
+
+    if (isIdentity())
+        return "identity";
+
+    AffineTransform::DecomposedType decomposition;
+    decompose(decomposition);
+
+    if (isIdentityOrTranslation())
+        return String::format("translation(%lg,%lg)", decomposition.translateX, decomposition.translateY);
+
+    return String::format("translation(%lg,%lg), scale(%lg,%lg), angle(%lgrad), remainder(%lg,%lg,%lg,%lg)",
+        decomposition.translateX,
+        decomposition.translateY,
+        decomposition.scaleX,
+        decomposition.scaleY,
+        decomposition.angle,

[jbroman, 2016/08/21 16:21:07]

super-nit: up to you, but I'd expect deg to be more useful in practice (as I
think it's more common in the web and in our unit tests), but up to you.
(rad2deg in wtf/MathExtras.h if you agree)

[pdr., 2016/08/22 17:27:35]

begrudgingly done. Radians are the one true way but you're right that we mostly
use degrees. When in wrong Rome..

+        decomposition.remainderA,
+        decomposition.remainderB,
+        decomposition.remainderC,
+        decomposition.remainderD);
+}
+
 } // namespace blink