browser/test/functional: Factorize browser instanciation

We should just intantiate the browser in one place so that we can easily change it.
Moreover we benefit that to make it possible to change the browser path (FF).
This would enable testing several versions of the web browser.

browser/test/functional/browser_test.rb

@@ -41,9 +41,7 @@ class BrowserTest < MiniTest::Test
     end
       
     print "Open browser\n"
-    #$b = VidjilBrowser.new :safari
-    $b = VidjilBrowser.new :firefox
-    #$b = VidjilBrowser.new :chrome
+    $b = VidjilBrowser.new
 
     print "Resize\n"
     $b.window.resize_to(1500, 800)

browser/test/functional/segmenter_test.rb

@@ -10,9 +10,7 @@ class SegmenterTest < BrowserTest
     index_path = 'file://' + folder_path + '/browser/segmenter_page.html'
 
     print "Open browser\n"
-    #$b = VidjilBrowser.new :safari
-    $b = SegmenterBrowser.new :firefox
-    #$b = VidjilBrowser.new :chrome
+    $b = SegmenterBrowser.new
 
     print "Resize\n"
     $b.window.resize_to(1500, 800)

browser/test/functional/test_segmenter-page.rb

@@ -113,7 +113,7 @@ GGGGGAGGCTTGGTACAGCCTGGGGGGTCCCTGAGACTCTCCTGTGCAGCCTCTGGATTCACCTTCAGTAGCTACGACAT
 
     assert (right_coord_of_textarea < left_coord_of_scatterplot), "Textarea should be left of scatterplot"
   end
-  
+
   def test_zz_close
     close_everything
   end

browser/test/functional/vidjil_browser.rb

@@ -3,6 +3,15 @@ require 'watir-webdriver'
 
 class VidjilBrowser < Watir::Browser
 
+  def initialize
+    if ENV['WATIR_BROWSER_PATH']
+      print "Using custom browser location " + ENV['WATIR_BROWSER_PATH'] + "\n"
+      Selenium::WebDriver::Firefox.path = ENV['WATIR_BROWSER_PATH']
+    end
+    # :chrome or :safari
+    super :firefox
+  end
+
   # Return the text field that allows to edit a clone name
   def clone_name_editor
     return text_field(:id => 'new_name')