Add Length::isPercent and use it in tables.

third_party/WebKit/Source/platform/Length.h

Index: third_party/WebKit/Source/platform/Length.h
diff --git a/third_party/WebKit/Source/platform/Length.h b/third_party/WebKit/Source/platform/Length.h
index 6e267fee1928595015edf5fa74089126765b4fda..c8fcb3c3adf247b024112e805a4566bf2831cd34 100644
--- a/third_party/WebKit/Source/platform/Length.h
+++ b/third_party/WebKit/Source/platform/Length.h
@@ -262,6 +262,7 @@ public:
     bool isMaxContent() const { return type() == MaxContent; }
     bool isFillAvailable() const { return type() == FillAvailable; }
     bool isFitContent() const { return type() == FitContent; }
+    bool isPercent() const { return type() == Percent; }

[mstensho (USE GERRIT), 2016/08/31 20:30:33]

This is a great name for what it does. But what about hasPercent() now? Looks
confusing to me.

     bool hasPercent() const { return type() == Percent || type() == Calculated; }
 
     Length blend(const Length& from, double progress, ValueRange range) const