use action view erubis for rails 3

Change-Id: I1f9cb0a894ce7a1af63b03d432396f7d911c5bf6
Reviewed-on: https://gerrit.instructure.com/29790
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Cody Cutrer <cody@instructure.com>
Product-Review: James Williams  <jamesw@instructure.com>
QA-Review: James Williams  <jamesw@instructure.com>

vendor/plugins/rails_xss/lib/rails_xss/erubis.rb

@@ -1,44 +1,44 @@
-$stdout, stdout_saved = (Class.new do def puts(string); end; def write(string); end; end).new, $stdout
 if CANVAS_RAILS2
+  $stdout, stdout_saved = (Class.new do def puts(string); end; def write(string); end; end).new, $stdout
   require 'erubis/helpers/rails_helper'
-end
-$stdout = stdout_saved
 
-module RailsXss
-  class Erubis < ::Erubis::Eruby
-    def add_preamble(src)
-      src << "@output_buffer = ActiveSupport::SafeBuffer.new;"
-    end
+  $stdout = stdout_saved
 
-    def add_text(src, text)
-      return if text.empty?
-      src << "@output_buffer.safe_concat('" << escape_text(text) << "');"
-    end
+  module RailsXss
+    class Erubis < ::Erubis::Eruby
+      def add_preamble(src)
+        src << "@output_buffer = ActiveSupport::SafeBuffer.new;"
+      end
 
-    BLOCK_EXPR = /\s+(do|\{)(\s*\|[^|]*\|)?\s*\Z/
+      def add_text(src, text)
+        return if text.empty?
+        src << "@output_buffer.safe_concat('" << escape_text(text) << "');"
+      end
 
-    def add_expr_literal(src, code)
-      if code =~ BLOCK_EXPR
-        src << "@output_buffer.append= " << code
-      else
-        src << '@output_buffer << ((' << code << ').to_s);'
+      BLOCK_EXPR = /\s+(do|\{)(\s*\|[^|]*\|)?\s*\Z/
+
+      def add_expr_literal(src, code)
+        if code =~ BLOCK_EXPR
+          src << "@output_buffer.append= " << code
+        else
+          src << '@output_buffer << ((' << code << ').to_s);'
+        end
+      end
+
+      def add_expr_escaped(src, code)
+        src << '@output_buffer << ' << escaped_expr(code) << ';'
+      end
+
+      def add_postamble(src)
+        src << '@output_buffer.to_s'
       end
     end
-
-    def add_expr_escaped(src, code)
-      src << '@output_buffer << ' << escaped_expr(code) << ';'
-    end
-
-    def add_postamble(src)
-      src << '@output_buffer.to_s'
-    end
   end
-end
 
-if CANVAS_RAILS2
   Erubis::Helpers::RailsHelper.engine_class = RailsXss::Erubis
   Erubis::Helpers::RailsHelper.show_src = false
 else
-  ActionView::Template.register_default_template_handler :erb, RailsXss::Erubis
-  ActionView::Template.register_template_handler :rhtml, RailsXss::Erubis
-end
+  module RailsXss
+    Erubis = ActionView::Template::Handlers::Erubis
+  end
+end