Fix bug 307256, bug 307304, bug 307924 by disabling selection for XUL elements

by default.  r+sr=dbaron, with OKs from Neil and mconnor for the general idea
and the xul.css changes.

layout/base/nsStyleConsts.h

@@ -87,7 +87,8 @@
 #define NS_STYLE_USER_SELECT_TOGGLE     5
 #define NS_STYLE_USER_SELECT_TRI_STATE  6
 #define NS_STYLE_USER_SELECT_AUTO       7 // internal value - please use nsFrame::IsSelectable()
-#define NS_STYLE_USER_SELECT_MOZ_ALL    8 // force selection of all children - bug 48096
+#define NS_STYLE_USER_SELECT_MOZ_ALL    8 // force selection of all children, unless an ancestor has NONE set - bug 48096
+#define NS_STYLE_USER_SELECT_MOZ_NONE   9 // Like NONE, but doesn't change selection behavior for descendants whose user-select is not AUTO.
 
 // user-input
 #define NS_STYLE_USER_INPUT_NONE      0

layout/generic/nsFrame.cpp

@@ -1187,6 +1187,9 @@ nsFrame::IsSelectable(PRBool* aSelectable, PRUint8* aSelectStyle) const
   else
   if (selectStyle == NS_STYLE_USER_SELECT_MOZ_ALL)
     selectStyle = NS_STYLE_USER_SELECT_ALL;
+  else
+  if (selectStyle == NS_STYLE_USER_SELECT_MOZ_NONE)
+    selectStyle = NS_STYLE_USER_SELECT_NONE;
 
   // return stuff
   if (aSelectable)

layout/style/forms.css

@@ -92,6 +92,7 @@ input {
   cursor: text;
   -moz-binding: url("chrome://global/content/platformHTMLBindings.xml#inputFields");
   text-indent: 0;
+  -moz-user-select: text;
 }
 
 input > .anonymous-div {
@@ -113,6 +114,7 @@ textarea {
   -moz-binding: url("chrome://global/content/platformHTMLBindings.xml#textAreas");
   -moz-appearance: textfield;
   text-indent: 0;
+  -moz-user-select: text;
 }
 
 textarea > scrollbar {

layout/style/nsCSSKeywordList.h

@@ -145,6 +145,7 @@ CSS_KEY(-moz-menuhover, _moz_menuhover)
 CSS_KEY(-moz-menuhovertext, _moz_menuhovertext)
 CSS_KEY(-moz-middle-with-baseline, _moz_middle_with_baseline)
 CSS_KEY(-moz-myanmar, _moz_myanmar)
+CSS_KEY(-moz-none, _moz_none)
 CSS_KEY(-moz-oriya, _moz_oriya)
 CSS_KEY(-moz-persian, _moz_persian)
 CSS_KEY(-moz-popup, _moz_popup)

layout/style/nsCSSProps.cpp

@@ -887,6 +887,7 @@ const PRInt32 nsCSSProps::kUserSelectKTable[] = {
   eCSSKeyword_toggle,     NS_STYLE_USER_SELECT_TOGGLE,
   eCSSKeyword_tri_state,  NS_STYLE_USER_SELECT_TRI_STATE,
   eCSSKeyword__moz_all,   NS_STYLE_USER_SELECT_MOZ_ALL,
+  eCSSKeyword__moz_none,  NS_STYLE_USER_SELECT_MOZ_NONE,
   eCSSKeyword_UNKNOWN,-1
 };
 

toolkit/content/xul.css

@@ -12,6 +12,7 @@
 
 * {
   -moz-user-focus: ignore;
+  -moz-user-select: -moz-none;
   display: -moz-box;
 }
 
@@ -652,12 +653,10 @@ spacer {
 
 description {
   -moz-binding: url("chrome://global/content/bindings/text.xml#text-base");
-  -moz-user-select: none;
 }
 
 label {
   -moz-binding: url("chrome://global/content/bindings/text.xml#text-label");
-  -moz-user-select: none;
 }
 
 label.text-link, label[onclick] {

xpfe/global/resources/content/xul.css

@@ -14,6 +14,7 @@
 
 * {
   -moz-user-focus: ignore;
+  -moz-user-select: -moz-none;
   display: -moz-box;
 }
 
@@ -611,12 +612,10 @@ spacer {
 
 description {
   -moz-binding: url("chrome://global/content/bindings/text.xml#text-base");
-  -moz-user-select: none;
 }
 
 label {
   -moz-binding: url("chrome://global/content/bindings/text.xml#text-label");
-  -moz-user-select: none;
 }
 
 label.text-link {