Backed out changeset 17ae7ed99b0b (bug 1201907) so I can cleanly back out another patch

--HG--
extra : rebase_source : 14f54738fff9f3696da1bbc933aa6692e5d11420

devtools/client/definitions.js

@@ -285,9 +285,14 @@ Tools.memory = {
   label: "Memory",
   panelLabel: "Memory Panel",
   tooltip: "Memory (keyboardshortcut)",
+  hiddenInOptions: true,
 
   isTargetSupported: function (target) {
-    return target.getTrait("heapSnapshots");
+    // TODO 1201907
+    // Once Fx44 lands, we should add a root trait `heapSnapshots`
+    // to indicate that the memory actor can handle this.
+    // Shouldn't make this change until Fx44, however.
+    return true; // target.getTrait("heapSnapshots");
   },
 
   build: function (frame, target) {

devtools/client/memory/components/toolbar.js

@@ -36,12 +36,12 @@ const Toolbar = module.exports = createClass({
       dom.div({ className: "devtools-toolbar" },
         dom.button({ className: `take-snapshot devtools-button`, onClick: onTakeSnapshotClick }),
 
-        dom.label({},
+        DOM.label({},
           "Breakdown by ",
-          dom.select({
+          DOM.select({
             className: `select-breakdown`,
             onChange: e => onBreakdownChange(e.target.value),
-          }, ...breakdowns.map(({ name, displayName }) => dom.option({ key: name, value: name }, displayName)))
+          }, ...breakdowns.map(({ name, displayName }) => DOM.option({ key: name, value: name }, displayName)))
         ),
 
         dom.label({},

devtools/server/actors/root.js

@@ -173,9 +173,6 @@ RootActor.prototype = {
     // Whether or not `getProfile()` supports specifying a `startTime`
     // and `endTime` to filter out samples. Fx40+
     profilerDataFilterable: true,
-    // Whether or not the MemoryActor's heap snapshot abilities are
-    // fully equipped to handle heap snapshots for the memory tool. Fx44+
-    heapSnapshots: true,
   },
 
   /**