initialize bitfields through a union to keep purify happy

content/html/style/src/nsHTMLStyleSheet.cpp

@@ -147,17 +147,21 @@ private:
 public:
   nsMapAttributesFunc mMapFunc;
   nsIHTMLAttributes*  mAttributes;
+  union {
+    struct {
       PRUint32        mHashSet: 1;
       PRUint32        mHashCode: 31;
     };
+    PRUint32          mBitfiledInitializer; // this is a hack to allow initialization without pruify complaining about a UMR
+  };
+};
 
 AttributeKey::AttributeKey(nsMapAttributesFunc aMapFunc, nsIHTMLAttributes* aAttributes)
   : mMapFunc(aMapFunc),
     mAttributes(aAttributes)
 {
   NS_ADDREF(mAttributes);
-  mHashSet = 0;
+  mBitfiledInitializer = 0;
-  mHashCode = 0;
 }
 
 AttributeKey::~AttributeKey(void)

layout/html/style/src/nsHTMLStyleSheet.cpp

@@ -147,17 +147,21 @@ private:
 public:
   nsMapAttributesFunc mMapFunc;
   nsIHTMLAttributes*  mAttributes;
+  union {
+    struct {
       PRUint32        mHashSet: 1;
       PRUint32        mHashCode: 31;
     };
+    PRUint32          mBitfiledInitializer; // this is a hack to allow initialization without pruify complaining about a UMR
+  };
+};
 
 AttributeKey::AttributeKey(nsMapAttributesFunc aMapFunc, nsIHTMLAttributes* aAttributes)
   : mMapFunc(aMapFunc),
     mAttributes(aAttributes)
 {
   NS_ADDREF(mAttributes);
-  mHashSet = 0;
+  mBitfiledInitializer = 0;
-  mHashCode = 0;
 }
 
 AttributeKey::~AttributeKey(void)

layout/style/nsHTMLStyleSheet.cpp

@@ -147,17 +147,21 @@ private:
 public:
   nsMapAttributesFunc mMapFunc;
   nsIHTMLAttributes*  mAttributes;
+  union {
+    struct {
       PRUint32        mHashSet: 1;
       PRUint32        mHashCode: 31;
     };
+    PRUint32          mBitfiledInitializer; // this is a hack to allow initialization without pruify complaining about a UMR
+  };
+};
 
 AttributeKey::AttributeKey(nsMapAttributesFunc aMapFunc, nsIHTMLAttributes* aAttributes)
   : mMapFunc(aMapFunc),
     mAttributes(aAttributes)
 {
   NS_ADDREF(mAttributes);
-  mHashSet = 0;
+  mBitfiledInitializer = 0;
-  mHashCode = 0;
 }
 
 AttributeKey::~AttributeKey(void)