diff --git a/mozilla/widget/public/nsIComboBox.h b/mozilla/widget/public/nsIComboBox.h
index aa5ed692408..698b7d5ba53 100644
--- a/mozilla/widget/public/nsIComboBox.h
+++ b/mozilla/widget/public/nsIComboBox.h
@@ -32,6 +32,11 @@
  */
 
 struct nsComboBoxInitData : public nsWidgetInitData {
+  nsComboBoxInitData()
+    : mDropDownHeight(0)
+  {
+  }
+
   PRUint32 mDropDownHeight; // in pixels
 };
 
diff --git a/mozilla/widget/public/nsILabel.h b/mozilla/widget/public/nsILabel.h
index 093113aeac7..21d900d676a 100644
--- a/mozilla/widget/public/nsILabel.h
+++ b/mozilla/widget/public/nsILabel.h
@@ -38,6 +38,11 @@ enum nsLabelAlignment {
   }; 
 
 struct nsLabelInitData : public nsWidgetInitData {
+  nsLabelInitData()
+    : mAlignment(eAlign_Left)
+  {
+  }
+
   nsLabelAlignment mAlignment;
 };
 
diff --git a/mozilla/widget/public/nsIListBox.h b/mozilla/widget/public/nsIListBox.h
index c6abdec447d..cb18db9f1f2 100644
--- a/mozilla/widget/public/nsIListBox.h
+++ b/mozilla/widget/public/nsIListBox.h
@@ -32,6 +32,11 @@
  */
 
 struct nsListBoxInitData : public nsWidgetInitData {
+  nsListBoxInitData()
+    : mMultiSelect(PR_FALSE)
+  {
+  }
+
   PRBool mMultiSelect;
 };
 
diff --git a/mozilla/widget/public/nsITextWidget.h b/mozilla/widget/public/nsITextWidget.h
index 0e812c17aa0..e60d7acd4d3 100644
--- a/mozilla/widget/public/nsITextWidget.h
+++ b/mozilla/widget/public/nsITextWidget.h
@@ -27,6 +27,12 @@
 
 
 struct nsTextWidgetInitData : public nsWidgetInitData {
+  nsTextWidgetInitData()
+    : mIsPassword(PR_FALSE),
+      mIsReadOnly(PR_FALSE)
+  {
+  }
+
   PRBool mIsPassword;
   PRBool mIsReadOnly;
 };
diff --git a/mozilla/widget/public/nsIWidget.h b/mozilla/widget/public/nsIWidget.h
index 305dea03526..07210484678 100644
--- a/mozilla/widget/public/nsIWidget.h
+++ b/mozilla/widget/public/nsIWidget.h
@@ -116,7 +116,13 @@ enum nsCursor {   ///(normal cursor,       usually rendered as an arrow)
  */
 
 struct nsWidgetInitData {
-  PRPackedBool  clipChildren;  // when painting exclude area occupied by child windows
+  nsWidgetInitData()
+    : clipChildren(PR_FALSE)
+  {
+  }
+
+  // when painting exclude area occupied by child windows
+  PRPackedBool  clipChildren;
 };
 
 /**