Fix Try Dart handling of Backspace that joins lines

tests/try/firefox-linemerges.applescript

+-- Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
+-- for details. All rights reserved. Use of this source code is governed by a
+-- BSD-style license that can be found in the LICENSE file.
+
+-- This: 'tell application "Firefox" to activate' doesn't seem to bring
+-- application in focus if it's not already open.
+do shell script "open -a Firefox"
+
+delay 3.0
+
+tell application "System Events"
+        --- Open Incognito window to avoid effect of caching of pages.
+        keystroke "p" using {command down, shift down}
+        
+        delay 1.0
+        
+        keystroke "l" using command down
+        
+        keystroke "http://localhost:8080/"
+        -- Simulate Enter key.
+        key code 36
+        
+        delay 10.0
+        
+        -- Refresh the page to reload the scripts
+        keystroke "r" using command down
+        
+        keystroke "l" using command down
+        
+        delay 1.0
+        
+        -- Simulate Tab key to get to 'Pick an example' dropdown
+        repeat 8 times

[ahe, 2014/09/05 13:10:44]

Fancy stuff :-)

+                key code 48
+        end repeat
+        
+        -- Simulate Down then Enter to select Hello, World
+        key code 125
+        key code 36
+        
+        delay 1.0
+        
+        keystroke "l" using command down
+        
+        delay 1.0
+        
+        -- Simulate Tab key to get to Code editor.
+        repeat 9 times
+                key code 48
+        end repeat
+        
+        -- Simulate sequence of Down keys to get to "print(greeting);" line
+        repeat 8 times
+                key code 125
+        end repeat
+        
+        -- Simulate Cmd-Right.
+        key code 124 using command down
+        
+        keystroke "print('c');"
+        
+        -- Simulate Left*11 to get to the beginning of "print('c');"
+        repeat 11 times
+                key code 123
+        end repeat
+        
+        -- Simulate Enter to split lines
+        key code 36
+        
+        -- Simulate Delete to join lines
+        key code 51
+        
+        -- Simulate Enter to split lines
+        key code 36
+        
+        -- Simulate Right*8 to get to right after the c in "print('c');"
+        repeat 8 times
+                key code 124
+        end repeat
+        
+        keystroke "d"
+        
+        delay 0.1
+        keystroke "a" using command down
+        delay 0.2
+        keystroke "c" using command down
+        
+        delay 1
+        set clipboardData to (the clipboard as text)
+        
+        if ("print('cd')" is not in (clipboardData as string)) then
+                error "print('cd')  is not in clipboardData: "
+        end if
+end tell
+
+tell application "Firefox" to quit
+
+display notification "Test passed" with title "Firefox test" sound name "Glass"