Streamline character width remeasurement to hopefully avoid exceptions

Previously, I was just remeasuring characters whenever the stylesheets
changed. I think there were situations in which the model changed, then
I remeasured characters prior to updating the view to match the model,
causing DOM exceptions. This switches the approach to only ever measure
characters after an update, ensuring the view always matches the model.

src/editor-component.coffee

@@ -28,7 +28,6 @@ EditorComponent = React.createClass
   updateRequested: false
   updatesPaused: false
   updateRequestedWhilePaused: false
-  characterWidthRemeasurementRequested: false
   cursorsMoved: false
   selectionChanged: false
   selectionAdded: false
@@ -43,7 +42,7 @@ EditorComponent = React.createClass
   scrollSensitivity: 0.4
   scrollViewMeasurementRequested: false
   measureLineHeightAndDefaultCharWidthWhenShown: false
-  remeasureCharacterWidthsWhenShown: false
+  remeasureCharacterWidthsIfVisibleAfterNextUpdate: false
   inputEnabled: true
   scrollViewMeasurementInterval: 100
   scopedCharacterWidthsChangeCount: null
@@ -655,7 +654,8 @@ EditorComponent = React.createClass
 
   onStylesheetsChanged: (stylesheet) ->
     @refreshScrollbars() if @containsScrollbarSelector(stylesheet)
-    @requestCharacterWidthRemeasurement()
+    @remeasureCharacterWidthsIfVisibleAfterNextUpdate = true
+    @requestUpdate() if @state.visible
 
   onScreenLinesChanged: (change) ->
     {editor} = @props
@@ -792,22 +792,12 @@ EditorComponent = React.createClass
       if @state.visible
         @remeasureCharacterWidths()
       else
-        @remeasureCharacterWidthsWhenShown = true
-    else if @remeasureCharacterWidthsWhenShown and @state.visible and not prevState.visible
+        @remeasureCharacterWidthsIfVisibleAfterNextUpdate = true
+    else if @remeasureCharacterWidthsIfVisibleAfterNextUpdate and @state.visible
+      @remeasureCharacterWidthsIfVisibleAfterNextUpdate = false
       @remeasureCharacterWidths()
 
-  requestCharacterWidthRemeasurement: ->
-    unless @characterWidthRemeasurementRequested
-      @characterWidthRemeasurementRequested = true
-      setImmediate =>
-        @characterWidthRemeasurementRequested = false
-        if @state.visible
-          @remeasureCharacterWidths()
-        else
-          @remeasureCharacterWidthsWhenShown = true
-
   remeasureCharacterWidths: ->
-    @remeasureCharacterWidthsWhenShown = false
     @refs.lines.remeasureCharacterWidths()
 
   onGutterWidthChanged: (@gutterWidth) ->