Would it be possible to provide as sample html test case for ease of bisecting.

Hello,
I created a Java test which shows the difference between the two browser versions. In this test I send the Keys CTRL + TAB to the browser to switch the tab which is in the foreground. This worked well for the chrome browsers (<= 53.0.2785.89), but does not work anymore for the chrome browser with the version (54.0.2840.16). The same thing happens if I send the Keys CTRL + t to open a new tab as stated in the original bug description.

    WebDriver driver = ...;

    // Load a page on the first tab.
    driver.get("https://www.google.com");

    // For testing purposes I use Thread.sleep to add some pauses to actually see what happens.
    Thread.sleep(1000);

    // Save handle of the first window.
    final String firstWindow = driver.getWindowHandle();

    // Open a new tab.
    org.openqa.selenium.JavascriptExecutor executor =
        (org.openqa.selenium.JavascriptExecutor) driver;
    executor.executeScript("window.open()");

    // Identify handle of the second window.
    ArrayList<String> tabs = new ArrayList<String>(driver.getWindowHandles());
    assertThat(tabs).hasSize(2);
    assertThat(tabs).contains(firstWindow);
    String secondWindow = tabs.get(0).equals(firstWindow) ? tabs.get(1) : tabs.get(0);

    // Switch driver to the second tab.
    driver.switchTo().window(secondWindow);
    // Load maps on the second tab.
    driver.get("https://maps.google.com");

    Thread.sleep(1000);

    // ######################################
    // Bring the first tab to the foreground.
    // This works for Chrome (53.0.2785.89), but does not do anything for Chrome (54.0.2840.16).
    // We need this to change the tab which is currently in the foreground, because we need our test
    // to fire the event when a tab gets the focus.
    new Actions(driver).keyDown(Keys.CONTROL).sendKeys(Keys.TAB).keyUp(Keys.CONTROL).perform();
    // ######################################

    Thread.sleep(1000);

    // Switch driver back to the first tab.
    driver.switchTo().window(firstWindow);
    // Close first tab.
    driver.close();

Cc'ing samuong@ for help in further investigation of this.

This is a duplicate of  issue chromedriver:1554 .