[Site Isolation] Context menu events are always sent to the main frame

https://bugs.webkit.org/show_bug.cgi?id=269217
rdar://122819286

Reviewed by Alex Christensen.

Context menu events should not be handled if the mouse event hit a remote frame.

* LayoutTests/http/tests/site-isolation/mouse-events/context-menu-main-frame-event-expected.txt: Added.
* LayoutTests/http/tests/site-isolation/mouse-events/context-menu-main-frame-event.html: Added.
* LayoutTests/http/tests/site-isolation/mouse-events/resources/context-menu-event-listener.html: Added.
* Source/WebKit/WebProcess/WebPage/WebFrame.cpp:
(WebKit::WebFrame::handleMouseEvent):

Canonical link: https://commits.webkit.org/274516@main

LayoutTests/http/tests/site-isolation/mouse-events/context-menu-main-frame-event-expected.txt

@@ -0,0 +1,10 @@
+Verifies that the iframe receives a context menu event and the main frame does not.
+
+On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".
+
+
+PASS iframe received context menu event.
+PASS successfullyParsed is true
+
+TEST COMPLETE
+

LayoutTests/http/tests/site-isolation/mouse-events/context-menu-main-frame-event.html

@@ -0,0 +1,28 @@
+<!-- webkit-test-runner [ SiteIsolationEnabled=true ] -->
+<script src="/js-test-resources/js-test.js"></script>
+<script>
+description("Verifies that the iframe receives a context menu event and the main frame does not.");
+jsTestIsAsync = true;
+
+addEventListener("message", (event) => {
+    if (event.data == "contextmenu") {
+        testPassed("iframe received context menu event.");
+        finishJSTest();
+    }
+});
+
+addEventListener("contextmenu", () => {
+    testFailed("Main frame contextmenu event listener was called.");
+    finishJSTest();
+});
+
+function onLoad() {
+    let frame = document.getElementById("frame");
+    let x = frame.offsetParent.offsetLeft + frame.offsetLeft + frame.offsetWidth / 2;
+    let y = frame.offsetParent.offsetTop + frame.offsetTop + frame.offsetHeight / 2;
+    eventSender.mouseMoveTo(x, y);
+    eventSender.mouseDown(2);
+    eventSender.mouseUp(2);
+}
+</script>
+<iframe onload="onLoad()" id="frame" src="http://localhost:8000/site-isolation/mouse-events/resources/context-menu-event-listener.html"></iframe>

LayoutTests/http/tests/site-isolation/mouse-events/resources/context-menu-event-listener.html

@@ -0,0 +1,5 @@
+<script>
+addEventListener("contextmenu", () => {
+    window.parent.postMessage("contextmenu", "*"); 
+});
+</script>

Source/WebKit/WebProcess/WebPage/WebFrame.cpp

@@ -1256,7 +1256,7 @@ WebCore::HandleUserInputEventResult WebFrame::handleMouseEvent(const WebMouseEve
 
         auto mousePressEventResult = coreLocalFrame->eventHandler().handleMousePressEvent(platformMouseEvent);
 #if ENABLE(CONTEXT_MENU_EVENT)
-        if (isContextClick(platformMouseEvent))
+        if (isContextClick(platformMouseEvent) && !mousePressEventResult.remoteUserInputEventData())
             mousePressEventResult.setHandled(handleContextMenuEvent(platformMouseEvent));
 #endif
         return mousePressEventResult;