Bug 1603176: Install target-switing mechanism. r=jdescottes

Depends on D61347

Differential Revision: https://phabricator.services.mozilla.com/D61348

--HG--
extra : moz-landing-system : lando

devtools/client/memory/initializer.js

@@ -23,7 +23,7 @@ let root, store, unsubscribe;
 
 const initialize = async function() {
   // Exposed by panel.js
-  const { gFront, gToolbox, gHeapAnalysesClient } = window;
+  const { gToolbox, gHeapAnalysesClient } = window;
 
   root = document.querySelector("#app");
   store = Store();
@@ -35,13 +35,14 @@ const initialize = async function() {
   ReactDOM.render(provider, root);
   unsubscribe = store.subscribe(onStateChange);
 
-  // Connect memory front and component.
-  store.dispatch(updateMemoryFront(gFront));
-
   // Exposed for tests.
   window.gStore = store;
 };
 
+const updateFront = front => {
+  store.dispatch(updateMemoryFront(front));
+};
+
 const destroy = function() {
   const ok = ReactDOM.unmountComponentAtNode(root);
   assert(
@@ -76,4 +77,4 @@ function onStateChange() {
   isHighlighted = isRecording;
 }
 
-module.exports = { initialize, destroy };
+module.exports = { initialize, updateFront, destroy };

devtools/client/memory/panel.js

@@ -21,36 +21,38 @@ function MemoryPanel(iframeWindow, toolbox) {
   }).require;
   this.initializer = browserRequire("devtools/client/memory/initializer");
 
+  this._onTargetAvailable = this._onTargetAvailable.bind(this);
+
   EventEmitter.decorate(this);
 }
 
 MemoryPanel.prototype = {
   async open() {
-    if (this._opening) {
-      return this._opening;
-    }
-
     this.panelWin.gToolbox = this._toolbox;
-    this.panelWin.gFront = await this.target.getFront("memory");
     this.panelWin.gHeapAnalysesClient = new HeapAnalysesClient();
 
-    await this.panelWin.gFront.attach();
+    await this.initializer.initialize();
 
-    this._opening = this.initializer.initialize().then(() => {
-      this.isReady = true;
-      this.emit("ready");
-      return this;
-    });
+    await this._toolbox.targetList.watchTargets(
+      [this._toolbox.targetList.TYPES.FRAME],
+      this._onTargetAvailable
+    );
 
-    return this._opening;
+    this.emit("ready");
+
+    return this;
+  },
+
+  async _onTargetAvailable({ targetFront, isTopLevel }) {
+    if (isTopLevel) {
+      const front = await targetFront.getFront("memory");
+      await front.attach();
+      this.initializer.updateFront(front);
+    }
   },
 
   // DevToolPanel API
 
-  get target() {
-    return this._toolbox.target;
-  },
-
   destroy() {
     // Make sure this panel is not already destroyed.
     if (this._destroyed) {
@@ -58,14 +60,15 @@ MemoryPanel.prototype = {
     }
     this._destroyed = true;
 
+    this._toolbox.targetList.unwatchTargets(
+      [this._toolbox.targetList.TYPES.FRAME],
+      this._onTargetAvailable
+    );
+
     this.initializer.destroy();
 
-    // Destroy front to ensure packet handler is removed from client
-    this.panelWin.gFront.destroy();
     this.panelWin.gHeapAnalysesClient.destroy();
     this.panelWin = null;
-    this._opening = null;
-    this.isReady = false;
     this.emit("destroyed");
   },
 };

devtools/client/memory/test/browser/browser_memory_allocationStackDisplay_01.js

@@ -20,8 +20,8 @@ const TEST_URL =
 
 this.test = makeMemoryTest(TEST_URL, async function({ tab, panel }) {
   const heapWorker = panel.panelWin.gHeapAnalysesClient;
-  const front = panel.panelWin.gFront;
   const { getState, dispatch } = panel.panelWin.gStore;
+  const front = getState().front;
   const doc = panel.panelWin.document;
 
   dispatch(changeView(viewState.CENSUS));

devtools/client/memory/test/browser/browser_memory_keyboard-snapshot-list.js

@@ -20,9 +20,9 @@ this.test = makeMemoryTest(TEST_URL, async function({ panel }) {
   requestLongerTimeout(2);
 
   const heapWorker = panel.panelWin.gHeapAnalysesClient;
-  const front = panel.panelWin.gFront;
   const store = panel.panelWin.gStore;
   const { dispatch } = store;
+  const front = store.getState().front;
   const doc = panel.panelWin.document;
 
   dispatch(changeView(viewState.CENSUS));

devtools/client/memory/test/browser/browser_memory_keyboard.js

@@ -39,9 +39,9 @@ function waitUntilExpanded(store, node) {
 
 this.test = makeMemoryTest(TEST_URL, async function({ tab, panel }) {
   const heapWorker = panel.panelWin.gHeapAnalysesClient;
-  const front = panel.panelWin.gFront;
   const store = panel.panelWin.gStore;
   const { getState, dispatch } = store;
+  const front = getState().front;
   const doc = panel.panelWin.document;
 
   dispatch(changeView(viewState.CENSUS));

devtools/client/memory/test/browser/browser_memory_no_allocation_stacks.js

@@ -17,8 +17,8 @@ const TEST_URL =
 
 this.test = makeMemoryTest(TEST_URL, async function({ tab, panel }) {
   const heapWorker = panel.panelWin.gHeapAnalysesClient;
-  const front = panel.panelWin.gFront;
   const { getState, dispatch } = panel.panelWin.gStore;
+  const front = getState().front;
   const doc = panel.panelWin.document;
 
   dispatch(changeView(viewState.CENSUS));

devtools/client/memory/test/browser/browser_memory_no_auto_expand.js

@@ -17,8 +17,8 @@ const TEST_URL =
 
 this.test = makeMemoryTest(TEST_URL, async function({ tab, panel }) {
   const heapWorker = panel.panelWin.gHeapAnalysesClient;
-  const front = panel.panelWin.gFront;
   const { getState, dispatch } = panel.panelWin.gStore;
+  const front = getState().front;
   const doc = panel.panelWin.document;
 
   dispatch(changeView(viewState.CENSUS));

devtools/client/memory/test/browser/browser_memory_percents_01.js

@@ -29,8 +29,8 @@ function checkCells(cells) {
 
 this.test = makeMemoryTest(TEST_URL, async function({ tab, panel }) {
   const heapWorker = panel.panelWin.gHeapAnalysesClient;
-  const front = panel.panelWin.gFront;
   const { getState, dispatch } = panel.panelWin.gStore;
+  const front = getState().front;
   const doc = panel.panelWin.document;
 
   dispatch(changeView(viewState.CENSUS));

devtools/client/memory/test/browser/browser_memory_refresh_does_not_leak.js

@@ -54,7 +54,7 @@ const DESCRIPTION = {
 };
 
 this.test = makeMemoryTest(TEST_URL, async function({ tab, panel }) {
-  const front = panel.panelWin.gFront;
+  const front = panel.panelWin.gStore.getState().front;
 
   const startWindows = await getWindowsInSnapshot(front);
   dumpn(

devtools/client/memory/test/browser/browser_memory_transferHeapSnapshot_e10s_01.js

@@ -12,7 +12,7 @@
 const TEST_URL = "data:text/html,<html><body></body></html>";
 
 this.test = makeMemoryTest(TEST_URL, async function({ tab, panel }) {
-  const memoryFront = panel.panelWin.gFront;
+  const memoryFront = panel.panelWin.gStore.getState().front;
   ok(memoryFront, "Should get the MemoryFront");
 
   const snapshotFilePath = await memoryFront.saveHeapSnapshot({