initialize member variables to 0

layout/base/public/nsIFrame.h

@@ -79,6 +79,10 @@ struct nsReflowMetrics {
     maxElementSize = aMaxElementSize;
     posTopMargin = 0;
     posBottomMargin = 0;
+    width = 0;
+    height = 0;
+    ascent = 0;
+    descent = 0;
   }
 };
 

layout/generic/nsIFrame.h

@@ -79,6 +79,10 @@ struct nsReflowMetrics {
     maxElementSize = aMaxElementSize;
     posTopMargin = 0;
     posBottomMargin = 0;
+    width = 0;
+    height = 0;
+    ascent = 0;
+    descent = 0;
   }
 };