Add unprefixed -webkit-line-break as an alias to import csswg-test

third_party/WebKit/Source/core/frame/UseCounter.cpp

Index: third_party/WebKit/Source/core/frame/UseCounter.cpp
diff --git a/third_party/WebKit/Source/core/frame/UseCounter.cpp b/third_party/WebKit/Source/core/frame/UseCounter.cpp
index 79272a3075bb1af7a4b11567b0cf8e1fbf853488..efe30554389db92fc7ef965f0760d3838b25ad96 100644
--- a/third_party/WebKit/Source/core/frame/UseCounter.cpp
+++ b/third_party/WebKit/Source/core/frame/UseCounter.cpp
@@ -46,7 +46,7 @@ int totalPagesMeasuredCSSSampleId() {
 }
 
 // Make sure update_use_counter_css.py was run which updates histograms.xml.
-constexpr int kMaximumCSSSampleId = 555;
+constexpr int kMaximumCSSSampleId = 556;
 
 }  // namespace
 
@@ -1079,6 +1079,8 @@ int UseCounter::mapCSSPropertyIdToCSSSampleIdForHistogram(
       return 554;
     case CSSPropertyMaxBlockSize:
       return 555;
+    case CSSPropertyAliasLineBreak:
+      return 556;
     // 1. Add new features above this line (don't change the assigned numbers of
     // the existing items).
     // 2. Update kMaximumCSSSampleId with the new maximum value.