Bug 1085119 - Part 1: Make devtools css-logic consider column when choosing best rule r=tromey

This allows minified CSS to be displayed correctly, as in
http://jsfiddle.net/oy4rkyax/

MozReview-Commit-ID: F8buX4gYY2P

devtools/server/css-logic.js

@@ -915,6 +915,7 @@ function CssRule(cssSheet, domRule, element) {
     // parse domRule.selectorText on call to this.selectors
     this._selectors = null;
     this.line = domUtils.getRuleLine(this.domRule);
+    this.column = domUtils.getRuleColumn(this.domRule);
     this.source = this._cssSheet.shortSource + ":" + this.line;
     if (this.mediaText) {
       this.source += " @media " + this.mediaText;
@@ -1107,6 +1108,16 @@ CssSelector.prototype = {
     return this.cssRule.line;
   },
 
+  /**
+   * Retrieve the column of the parent CSSStyleRule in the parent CSSStyleSheet.
+   *
+   * @return {number} the column of the parent CSSStyleRule in the parent
+   * stylesheet.
+   */
+  get ruleColumn() {
+    return this.cssRule.column;
+  },
+
   /**
    * Retrieve specificity information for the current selector.
    *
@@ -1391,6 +1402,16 @@ CssSelectorInfo.prototype = {
     return this.selector.ruleLine;
   },
 
+  /**
+   * Retrieve the column of the parent CSSStyleRule in the parent CSSStyleSheet.
+   *
+   * @return {number} the column of the parent CSSStyleRule in the parent
+   * stylesheet.
+   */
+  get ruleColumn() {
+    return this.selector.ruleColumn;
+  },
+
   /**
    * Check if the selector comes from a browser-provided stylesheet.
    *
@@ -1458,6 +1479,13 @@ CssSelectorInfo.prototype = {
       return 1;
     }
 
+    if (this.ruleColumn > that.ruleColumn) {
+      return -1;
+    }
+    if (that.ruleColumn > this.ruleColumn) {
+      return 1;
+    }
+
     return 0;
   },