System tests: run Chrome in kiosk mode to stop treeGrid test failing (n…

…vaccess#12023)

* Chrome system tests: run Chrome in kiosk mode, which removes the need to press f6 1 or more times to move from the Chrome to the document.

* Linting

* Force another pr build.

tests/system/libraries/ChromeLib.py

@@ -51,6 +51,7 @@ def start_chrome(self, filePath):
 			" --force-renderer-accessibility"
 			" --suppress-message-center-popups"
 			" --disable-notifications"
+			" -kiosk"
 			f' "{filePath}"',
 			shell=True,
 			alias='chromeAlias',
@@ -92,18 +93,19 @@ def _wasStartMarkerSpoken(self, speech: str):
 		marker = ChromeLib._beforeMarker
 		return marker in speech and documentIndex < speech.index(marker)
 
-	def _moveToStartMarker(self, spy):
-		""" Press F6 until the start marker is spoken
+	def _waitForStartMarker(self, spy, lastSpeechIndex):
+		""" Wait until the page loads and NVDA reads the start marker.
 		@param spy:
 		@type spy: SystemTestSpy.speechSpyGlobalPlugin.NVDASpyLib
 		@return: None
 		"""
 		for i in range(10):  # set a limit on the number of tries.
-			# Small changes in Chrome mean the number of tab presses to get into the document can vary.
 			builtIn.sleep("0.5 seconds")  # ensure application has time to receive input
-			actualSpeech = self.getSpeechAfterKey('f6')
+			spy.wait_for_speech_to_finish()
+			actualSpeech = spy.get_speech_at_index_until_now(lastSpeechIndex)
 			if self._wasStartMarkerSpoken(actualSpeech):
 				break
+			lastSpeechIndex = spy.get_last_speech_index()
 		else:  # Exceeded the number of tries
 			spy.dump_speech_to_log()
 			builtIn.fail(
@@ -133,11 +135,7 @@ def prepareChrome(self, testCase: str) -> None:
 		# it is ready.
 		applicationTitle = f"{self._testCaseTitle}"
 		appTitleIndex = spy.wait_for_specific_speech(applicationTitle, afterIndex=lastSpeechIndex)
-		spy.wait_for_speech_to_finish()
-
-		afterTitleSpeech = spy.get_speech_at_index_until_now(appTitleIndex)
-		if not self._wasStartMarkerSpoken(afterTitleSpeech):
-			self._moveToStartMarker(spy)
+		self._waitForStartMarker(spy, appTitleIndex)
 
 
 	@staticmethod