Update window commands to use W3C End points

When speaking to a W3C End point we should use the W3C Window endpoints
instead of the JSONWP ones.

Author: AutomatedTester

py/selenium/webdriver/remote/command.py

@@ -56,7 +56,9 @@ class Command(object):
     SUBMIT_ELEMENT = "submitElement"
     UPLOAD_FILE = "uploadFile"
     GET_CURRENT_WINDOW_HANDLE = "getCurrentWindowHandle"
+    W3C_GET_CURRENT_WINDOW_HANDLE = "w3cGetCurrentWindowHandle"
     GET_WINDOW_HANDLES = "getWindowHandles"
+    W3C_GET_WINDOW_HANDLES = "w3cGetWindowHandles"
     GET_WINDOW_SIZE = "getWindowSize"
     W3C_GET_WINDOW_SIZE = "w3cGetWindowSize"
     W3C_GET_WINDOW_POSITION = "w3cGetWindowPosition"

py/selenium/webdriver/remote/remote_connection.py

@@ -233,8 +233,12 @@ def __init__(self, remote_server_addr, keep_alive=False, resolve_ip=True):
             Command.QUIT: ('DELETE', '/session/$sessionId'),
             Command.GET_CURRENT_WINDOW_HANDLE:
                 ('GET', '/session/$sessionId/window_handle'),
+            Command.W3C_GET_CURRENT_WINDOW_HANDLE:
+                ('GET', '/session/$sessionId/window'),
             Command.GET_WINDOW_HANDLES:
                 ('GET', '/session/$sessionId/window_handles'),
+            Command.W3C_GET_WINDOW_HANDLES:
+                ('GET', '/session/$sessionId/window/handles'),
             Command.GET: ('POST', '/session/$sessionId/url'),
             Command.GO_FORWARD: ('POST', '/session/$sessionId/forward'),
             Command.GO_BACK: ('POST', '/session/$sessionId/back'),

py/selenium/webdriver/remote/webdriver.py

@@ -553,7 +553,10 @@ def current_window_handle(self):
         :Usage:
             driver.current_window_handle
         """
-        return self.execute(Command.GET_CURRENT_WINDOW_HANDLE)['value']
+        if self.w3c:
+            return self.execute(Command.W3C_GET_CURRENT_WINDOW_HANDLE)['value']
+        else:
+            return self.execute(Command.GET_CURRENT_WINDOW_HANDLE)['value']
 
     @property
     def window_handles(self):
@@ -563,7 +566,10 @@ def window_handles(self):
         :Usage:
             driver.window_handles
         """
-        return self.execute(Command.GET_WINDOW_HANDLES)['value']
+        if self.w3c:
+            return self.execute(Command.W3C_GET_WINDOW_HANDLES)['value']
+        else:
+            return self.execute(Command.GET_WINDOW_HANDLES)['value']
 
     def maximize_window(self):
         """