Set font size and family directly on editor element

Previously this was set via a style tag which ate up a lot of spec
time and seemed to be functionally equivalent to just setting the
style directly on the element instead of finding and adding/removing
style tags.

spec/editor-spec.coffee

@@ -288,15 +288,13 @@ describe "Editor", ->
 
   describe "font family", ->
     beforeEach ->
-      expect(editor.css('font-family')).not.toBe 'Courier'
+      expect(editor.css('font-family')).toBe 'Courier'
 
     it "when there is no config in fontFamily don't set it", ->
-      expect($("head style.font-family")).not.toExist()
+      atom.config.set('editor.fontFamily', null)
+      expect(editor.css('font-family')).toBe ''
 
     describe "when the font family changes", ->
-      afterEach ->
-        editor.clearFontFamily()
-
       it "updates the font family of editors and recalculates dimensions critical to cursor positioning", ->
         editor.attachToDom(12)
         lineHeightBefore = editor.lineHeight
@@ -305,7 +303,6 @@ describe "Editor", ->
 
         config.set("editor.fontFamily", "PCMyungjo")
         expect(editor.css('font-family')).toBe 'PCMyungjo'
-        expect($("head style.editor-font-family").text()).toMatch "{font-family: PCMyungjo}"
         expect(editor.charWidth).not.toBe charWidthBefore
         expect(editor.getCursorView().position()).toEqual { top: 5 * editor.lineHeight, left: 6 * editor.charWidth }
 
@@ -319,8 +316,7 @@ describe "Editor", ->
       expect(editor.css('font-size')).not.toBe "10px"
 
     it "sets the initial font size based on the value from config", ->
-      expect($("head style.font-size")).toExist()
-      expect($("head style.font-size").text()).toMatch "{font-size: #{config.get('editor.fontSize')}px}"
+      expect(editor.css('font-size')).toBe "#{config.get('editor.fontSize')}px"
 
     describe "when the font size changes", ->
       it "updates the font sizes of editors and recalculates dimensions critical to cursor positioning", ->
@@ -406,9 +402,6 @@ describe "Editor", ->
         beforeEach ->
           editor.setFontFamily('sans-serif')
 
-        afterEach ->
-          editor.clearFontFamily()
-
         it "positions the cursor to the clicked row and column", ->
           {top, left} = editor.pixelOffsetForScreenPosition([3, 30])
           editor.renderedLines.trigger mousedownEvent(pageX: left, pageY: top)
@@ -917,9 +910,6 @@ describe "Editor", ->
         beforeEach ->
           editor.setFontFamily('sans-serif')
 
-        afterEach ->
-          editor.clearFontFamily()
-
         it "correctly positions the cursor", ->
           editor.setCursorBufferPosition([3, 30])
           expect(editor.getCursorView().position()).toEqual {top: 3 * editor.lineHeight, left: 178}

src/editor.coffee

@@ -960,14 +960,7 @@ class Editor extends View
   #
   # fontSize - A {Number} indicating the font size in pixels.
   setFontSize: (fontSize) ->
-    headTag = $("head")
-    styleTag = headTag.find("style.font-size")
-    if styleTag.length == 0
-      styleTag = $$ -> @style class: 'font-size'
-      headTag.append styleTag
-
-    styleTag.text(".editor {font-size: #{fontSize}px}")
-
+    @css('font-size', "#{fontSize}px}")
     if @isOnDom()
       @redraw()
     else
@@ -982,18 +975,8 @@ class Editor extends View
   # Sets the font family for the editor.
   #
   # fontFamily - A {String} identifying the CSS `font-family`,
-  setFontFamily: (fontFamily) ->
-    headTag = $("head")
-    styleTag = headTag.find("style.editor-font-family")
-
-    if fontFamily?
-      if styleTag.length == 0
-        styleTag = $$ -> @style class: 'editor-font-family'
-        headTag.append styleTag
-      styleTag.text(".editor {font-family: #{fontFamily}}")
-    else
-      styleTag.remove()
-
+  setFontFamily: (fontFamily='') ->
+    @css('font-family', fontFamily)
     @redraw()
 
   # Gets the font family for the editor.
@@ -1001,11 +984,7 @@ class Editor extends View
   # Returns a {String} identifying the CSS `font-family`,
   getFontFamily: -> @css("font-family")
 
-  # Clears the CSS `font-family` property from the editor.
-  clearFontFamily: ->
-    $('head style.editor-font-family').remove()
-
-  # Clears the CSS `font-family` property from the editor.
+  # Redraw the editor
   redraw: ->
     return unless @hasParent()
     return unless @attached