Bug 1688569 - [devtools] Watch DOM mutation breakpoints on all targets r=ochameau

Differential Revision: https://phabricator.services.mozilla.com/D103072

devtools/client/debugger/test/mochitest/browser_dbg-dom-mutation-breakpoints-fission.js

@@ -68,48 +68,42 @@ add_task(async function() {
   const mutationItem = await waitForElement(dbg, "domMutationItem");
   ok(mutationItem, "A DOM mutation breakpoint exists");
 
-  if (isFissionEnabled()) {
-    // The behavior of the else branch currently times out on fission.
-    // See Bug 1688569.
-    todo(false, "Disabling DOM breakpoints in frames fails with Fission");
-  } else {
-    mutationItem.scrollIntoView();
+  mutationItem.scrollIntoView();
 
-    info("Enabling and disabling the DOM mutation breakpoint works");
-    const checkbox = mutationItem.querySelector("input");
-    checkbox.click();
-    await waitFor(() => !checkbox.checked);
+  info("Enabling and disabling the DOM mutation breakpoint works");
+  const checkbox = mutationItem.querySelector("input");
+  checkbox.click();
+  await waitFor(() => !checkbox.checked);
 
-    info(
-      "Click the button in the remote iframe, should not hit the breakpoint"
-    );
-    BrowserTestUtils.synthesizeMouse("button", 0, 0, {}, frameBC);
+  info(
+    "Click the button in the remote iframe, should not hit the breakpoint"
+  );
+  BrowserTestUtils.synthesizeMouse("button", 0, 0, {}, frameBC);
 
-    info("Wait until the input is enabled");
-    await asyncWaitUntil(() =>
-      SpecialPowers.spawn(gBrowser.selectedBrowser, [], function() {
-        return SpecialPowers.spawn(
-          content.document.querySelector("iframe"),
-          [],
-          () => !content.document.querySelector("input").disabled
-        );
-      })
-    );
-    is(isPaused(dbg), false, "DOM breakpoint should not have been hit");
-
-    info("Restore the disabled attribute");
-    await SpecialPowers.spawn(gBrowser.selectedBrowser, [], function() {
+  info("Wait until the input is enabled");
+  await asyncWaitUntil(() =>
+    SpecialPowers.spawn(gBrowser.selectedBrowser, [], function() {
       return SpecialPowers.spawn(
         content.document.querySelector("iframe"),
         [],
-        () =>
-          !content.document.querySelector("input").setAttribute("disabled", "")
+        () => !content.document.querySelector("input").disabled
       );
-    });
+    })
+  );
+  is(isPaused(dbg), false, "DOM breakpoint should not have been hit");
 
-    checkbox.click();
-    await waitFor(() => checkbox.checked);
-  }
+  info("Restore the disabled attribute");
+  await SpecialPowers.spawn(gBrowser.selectedBrowser, [], function() {
+    return SpecialPowers.spawn(
+      content.document.querySelector("iframe"),
+      [],
+      () =>
+        !content.document.querySelector("input").setAttribute("disabled", "")
+    );
+  });
+
+  checkbox.click();
+  await waitFor(() => checkbox.checked);
 
   info("Click the button in the remote iframe, to trigger the breakpoint");
   BrowserTestUtils.synthesizeMouse("button", 0, 0, {}, frameBC);

devtools/client/framework/toolbox.js

@@ -701,12 +701,14 @@ Toolbox.prototype = {
       targetFront.on("navigate", this._onNavigate);
       targetFront.on("frame-update", this._updateFrames);
       targetFront.on("inspect-object", this._onInspectObject);
-
-      targetFront.watchFronts("inspector", async inspectorFront => {
-        registerWalkerListeners(this.store, inspectorFront.walker);
-      });
     }
 
+    // Walker listeners allow to monitor DOM Mutation breakpoint updates.
+    // All targets should be monitored.
+    targetFront.watchFronts("inspector", async inspectorFront => {
+      registerWalkerListeners(this.store, inspectorFront.walker);
+    });
+
     const { threadFront } = targetFront;
     if (threadFront) {
       // threadFront listeners are removed when the thread is destroyed