Bug 1391217 - Remove unused @namespace svg at-rules. r=dao

MozReview-Commit-ID: AtKfipt5MUZ

browser/base/content/browser.css

@@ -4,7 +4,6 @@
 
 @namespace url("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul");
 @namespace html url("http://www.w3.org/1999/xhtml");
-@namespace svg url("http://www.w3.org/2000/svg");
 
 :root {
   --panelui-subview-transition-duration: 150ms;

browser/themes/linux/browser.css

@@ -8,7 +8,6 @@
 
 @namespace url("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul");
 @namespace html url("http://www.w3.org/1999/xhtml");
-@namespace svg url("http://www.w3.org/2000/svg");
 
 %include ../shared/browser.inc.css
 

browser/themes/osx/browser.css

@@ -9,7 +9,6 @@
 
 @namespace url("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul");
 @namespace html url("http://www.w3.org/1999/xhtml");
-@namespace svg url("http://www.w3.org/2000/svg");
 
 %include ../shared/browser.inc.css
 

browser/themes/windows/browser.css

@@ -6,7 +6,6 @@
 
 @namespace url("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul");
 @namespace html url("http://www.w3.org/1999/xhtml");
-@namespace svg url("http://www.w3.org/2000/svg");
 
 %include ../shared/browser.inc.css