--- a/dom/browser-element/mochitest/browserElement_Find.js
+++ b/dom/browser-element/mochitest/browserElement_Find.js
@@ -18,127 +18,131 @@ function runTest() {
     return new Promise((resolve) => {
       iframe.addEventListener(eventName, function(...args) {
         resolve(...args);
       }, {once: true});
     });
   }
 
   // Test if all key=>value pairs in o1 are present in o2.
-  const c = (o1, o2) => Object.keys(o1).every(k => o1[k] == o2[k]);
+  const c = (o1, o2, i) => {
+    for (let k of Object.keys(o1)) {
+      is(o1[k], o2[k], `Test ${i} should match for key ${k}`);
+    }
+  }
 
   let testCount = 0;
 
   once('mozbrowserloadend').then(() => {
     iframe.findAll('foo', 'case-insensitive');
     return once('mozbrowserfindchange');
   }).then(({detail}) => {
-    ok(c(detail, {
+    c(detail, {
       msg_name: "findchange",
       active: true,
       searchString: 'foo',
       searchLimit: 1000,
       activeMatchOrdinal: 1,
       numberOfMatches: 5,
-    }), `test ${testCount++}`);
+    }, testCount++);
     iframe.findNext('forward');
     return once('mozbrowserfindchange');
   }).then(({detail}) => {
-    ok(c(detail, {
+    c(detail, {
       msg_name: "findchange",
       active: true,
       searchString: 'foo',
       searchLimit: 1000,
       activeMatchOrdinal: 2,
       numberOfMatches: 5,
-    }), `test ${testCount++}`);
+    }, testCount++);
     iframe.findNext('backward');
     return once('mozbrowserfindchange');
   }).then(({detail}) => {
-    ok(c(detail, {
+    c(detail, {
       msg_name: "findchange",
       active: true,
       searchString: 'foo',
       searchLimit: 1000,
       activeMatchOrdinal: 1,
       numberOfMatches: 5,
-    }), `test ${testCount++}`);
+    }, testCount++);
     iframe.findAll('xxx', 'case-sensitive');
     return once('mozbrowserfindchange');
   }).then(({detail}) => {
-    ok(c(detail, {
+    c(detail, {
       msg_name: "findchange",
       active: true,
       searchString: 'xxx',
       searchLimit: 1000,
       activeMatchOrdinal: 0,
       numberOfMatches: 0,
-    }), `test ${testCount++}`);
+    }, testCount++);
     iframe.findAll('bar', 'case-insensitive');
     return once('mozbrowserfindchange');
   }).then(({detail}) => {
-    ok(c(detail, {
+    c(detail, {
       msg_name: "findchange",
       active: true,
       searchString: 'bar',
       searchLimit: 1000,
       activeMatchOrdinal: 1,
       numberOfMatches: 4,
-    }), `test ${testCount++}`);
+    }, testCount++);
     iframe.findNext('forward');
     return once('mozbrowserfindchange');
   }).then(({detail}) => {
-    ok(c(detail, {
+    c(detail, {
       msg_name: "findchange",
       active: true,
       searchString: 'bar',
       searchLimit: 1000,
       activeMatchOrdinal: 2,
       numberOfMatches: 4,
-    }), `test ${testCount++}`);
+    }, testCount++);
     iframe.findNext('forward');
     return once('mozbrowserfindchange');
   }).then(({detail}) => {
-    ok(c(detail, {
+    c(detail, {
       msg_name: "findchange",
       active: true,
       searchString: 'bar',
       searchLimit: 1000,
       activeMatchOrdinal: 3,
       numberOfMatches: 4,
-    }), `test ${testCount++}`);
+    }, testCount++);
     iframe.findNext('forward');
     return once('mozbrowserfindchange');
   }).then(({detail}) => {
-    ok(c(detail, {
+    c(detail, {
       msg_name: "findchange",
       active: true,
       searchString: 'bar',
       searchLimit: 1000,
       activeMatchOrdinal: 4,
       numberOfMatches: 4,
-    }), `test ${testCount++}`);
+    }, testCount++);
     iframe.findNext('forward');
     return once('mozbrowserfindchange');
   }).then(({detail}) => {
-    ok(c(detail, {
+    c(detail, {
       msg_name: "findchange",
       active: true,
       searchString: 'bar',
       searchLimit: 1000,
       activeMatchOrdinal: 1,
       numberOfMatches: 4,
-    }), `test ${testCount++}`);
+    }, testCount++);
     iframe.clearMatch();
     return once('mozbrowserfindchange');
   }).then(({detail}) => {
-    ok(c(detail, {
+    c(detail, {
       msg_name: "findchange",
       active: false
-    }), `test ${testCount++}`);
+    }, testCount++);
     SimpleTest.finish();
   });
 
   document.body.appendChild(iframe);
 
 }
 
 addEventListener('testready', runTest);

--- a/dom/browser-element/mochitest/chrome.ini
+++ b/dom/browser-element/mochitest/chrome.ini
@@ -31,16 +31,17 @@ support-files =
   file_illegal_web_manifest.html
 
 [test_browserElement_inproc_BackForward.html]
 [test_browserElement_inproc_BadScreenshot.html]
 [test_browserElement_inproc_DocumentFirstPaint.html]
 [test_browserElement_inproc_DOMRequestError.html]
 [test_browserElement_inproc_ExecuteScript.html]
 [test_browserElement_inproc_Find.html]
+disabled = Bug 1458393
 [test_browserElement_inproc_GetContentDimensions.html]
 [test_browserElement_inproc_GetScreenshot.html]
 [test_browserElement_inproc_GetScreenshotDppx.html]
 [test_browserElement_inproc_getWebManifest.html]
 [test_browserElement_inproc_NextPaint.html]
 [test_browserElement_inproc_PurgeHistory.html]
 [test_browserElement_inproc_ReloadPostRequest.html]
 disabled = no modal prompt on POST reload for chrome window