--- a/layout/style/nsStyleStruct.cpp
+++ b/layout/style/nsStyleStruct.cpp
@@ -40,20 +40,18 @@
 #include <algorithm>
 
 using namespace mozilla;
 
 static_assert((((1 << nsStyleStructID_Length) - 1) &
                ~(NS_STYLE_INHERIT_MASK)) == 0,
               "Not enough bits in NS_STYLE_INHERIT_MASK");
 
-// These are the limits that we choose to clamp grid line numbers to.
-// http://dev.w3.org/csswg/css-grid/#overlarge-grids
-const int32_t nsStyleGridLine::kMinLine = -10000;
-const int32_t nsStyleGridLine::kMaxLine = 10000;
+/* static */ const int32_t nsStyleGridLine::kMinLine;
+/* static */ const int32_t nsStyleGridLine::kMaxLine;
 
 static bool
 EqualURIs(nsIURI *aURI1, nsIURI *aURI2)
 {
   bool eq;
   return aURI1 == aURI2 ||    // handle null==null, and optimize
          (aURI1 && aURI2 &&
           NS_SUCCEEDED(aURI1->Equals(aURI2, &eq)) && // not equal on fail
@@ -817,17 +815,17 @@ nsStyleXUL::CalcDifference(const nsStyle
     return nsChangeHint_ReconstructFrame;
   }
   return NS_STYLE_HINT_REFLOW;
 }
 
 // --------------------
 // nsStyleColumn
 //
-/* static */ const uint32_t nsStyleColumn::kMaxColumnCount = 1000;
+/* static */ const uint32_t nsStyleColumn::kMaxColumnCount;
 
 nsStyleColumn::nsStyleColumn(StyleStructContext aContext)
   : mColumnCount(NS_STYLE_COLUMN_COUNT_AUTO)
   , mColumnWidth(eStyleUnit_Auto)
   , mColumnGap(eStyleUnit_Normal)
   , mColumnRuleColor(StyleComplexColor::CurrentColor())
   , mColumnRuleStyle(NS_STYLE_BORDER_STYLE_NONE)
   , mColumnFill(NS_STYLE_COLUMN_FILL_BALANCE)

--- a/layout/style/nsStyleStruct.h
+++ b/layout/style/nsStyleStruct.h
@@ -1593,19 +1593,21 @@ private:
 struct nsStyleGridLine
 {
   // http://dev.w3.org/csswg/css-grid/#typedef-grid-line
   // XXXmats we could optimize memory size here
   bool mHasSpan;
   int32_t mInteger;  // 0 means not provided
   nsString mLineName;  // Empty string means not provided.
 
+  // These are the limits that we choose to clamp grid line numbers to.
+  // http://dev.w3.org/csswg/css-grid/#overlarge-grids
   // mInteger is clamped to this range:
-  static const int32_t kMinLine;
-  static const int32_t kMaxLine;
+  static const int32_t kMinLine = -10000;
+  static const int32_t kMaxLine = 10000;
 
   nsStyleGridLine()
     : mHasSpan(false)
     , mInteger(0)
     // mLineName get its default constructor, the empty string
   {
   }
 
@@ -3467,17 +3469,17 @@ struct MOZ_NEEDS_MEMMOVABLE_MEMBERS nsSt
            nsChangeHint_ReflowChangesSizeOrPosition |
            nsChangeHint_ClearAncestorIntrinsics;
   }
 
   /**
    * This is the maximum number of columns we can process. It's used in both
    * nsColumnSetFrame and nsRuleNode.
    */
-  static const uint32_t kMaxColumnCount;
+  static const uint32_t kMaxColumnCount = 1000;
 
   uint32_t     mColumnCount; // [reset] see nsStyleConsts.h
   nsStyleCoord mColumnWidth; // [reset] coord, auto
   nsStyleCoord mColumnGap;   // [reset] coord, normal
 
   mozilla::StyleComplexColor mColumnRuleColor; // [reset]
   uint8_t      mColumnRuleStyle;  // [reset]
   uint8_t      mColumnFill;  // [reset] see nsStyleConsts.h