[bidi][java] Add browsing context activate command

Author: pujagani

java/src/org/openqa/selenium/bidi/browsingcontext/BrowsingContext.java

@@ -315,6 +315,10 @@ public void setViewport(double width, double height, double devicePixelRatio) {
                 devicePixelRatio)));
   }
 
+  public void activate() {
+    this.bidi.send(new Command<>("browsingContext.activate", Map.of(CONTEXT, id)));
+  }
+
   public void close() {
     // This might need more clean up actions once the behavior is defined.
     // Specially when last tab or window is closed.

java/test/org/openqa/selenium/bidi/browsingcontext/BrowsingContextTest.java

@@ -207,6 +207,22 @@ void canCloseATab() {
     assertThatExceptionOfType(BiDiException.class).isThrownBy(tab2::getTree);
   }
 
+  @Test
+  @NotYetImplemented(SAFARI)
+  @NotYetImplemented(IE)
+  void canActivateABrowsingContext() {
+    BrowsingContext window1 = new BrowsingContext(driver, driver.getWindowHandle());
+    // 2nd window is focused
+    BrowsingContext window2 = new BrowsingContext(driver, WindowType.WINDOW);
+
+    // We did not switch the driver, so we are running the script to check focus on 1st window
+    assertThat(getDocumentFocus()).isFalse();
+
+    window1.activate();
+
+    assertThat(getDocumentFocus()).isTrue();
+  }
+
   // TODO: Add a test for closing the last tab once the behavior is finalized
   // Refer: https://github.com/w3c/webdriver-bidi/issues/187
 
@@ -486,6 +502,10 @@ private String promptPage() {
                 "<p id=\"result\"></p>"));
   }
 
+  private boolean getDocumentFocus() {
+    return (boolean) ((JavascriptExecutor) driver).executeScript("return document.hasFocus();");
+  }
+
   @AfterEach
   public void quitDriver() {
     if (driver != null) {