diff --git a/browser/devtools/shadereditor/shadereditor.js b/browser/devtools/shadereditor/shadereditor.js
index ec6eafea366c..93019876eb2f 100644
--- a/browser/devtools/shadereditor/shadereditor.js
+++ b/browser/devtools/shadereditor/shadereditor.js
@@ -10,6 +10,7 @@ Cu.import("resource://gre/modules/XPCOMUtils.jsm");
 Cu.import("resource://gre/modules/Task.jsm");
 Cu.import("resource:///modules/devtools/SideMenuWidget.jsm");
 Cu.import("resource:///modules/devtools/ViewHelpers.jsm");
+Cu.import("resource://gre/modules/devtools/Console.jsm");
 
 const require = Cu.import("resource://gre/modules/devtools/Loader.jsm", {}).devtools.require;
 const promise = Cu.import("resource://gre/modules/Promise.jsm", {}).Promise;
@@ -123,26 +124,26 @@ let EventsHandler = {
   _onTabNavigated: function(event, {isFrameSwitching}) {
     switch (event) {
       case "will-navigate": {
-        Task.spawn(function*() {
-          // Make sure the backend is prepared to handle WebGL contexts.
-          if (!isFrameSwitching) {
-            gFront.setup({ reload: false });
-          }
+        // Make sure the backend is prepared to handle WebGL contexts.
+        if (!isFrameSwitching) {
+          gFront.setup({ reload: false });
+        }
+
+        // Reset UI.
+        ShadersListView.empty();
+        // When switching to an iframe, ensure displaying the reload button.
+        // As the document has already been loaded without being hooked.
+        if (isFrameSwitching) {
+          $("#reload-notice").hidden = false;
+          $("#waiting-notice").hidden = true;
+        } else {
+          $("#reload-notice").hidden = true;
+          $("#waiting-notice").hidden = false;
+        }
+
+        $("#content").hidden = true;
+        window.emit(EVENTS.UI_RESET);
 
-          // Reset UI.
-          ShadersListView.empty();
-          // When switching to an iframe, ensure displaying the reload button.
-          // As the document has already been loaded without being hooked.
-          if (isFrameSwitching) {
-            $("#reload-notice").hidden = false;
-            $("#waiting-notice").hidden = true;
-          } else {
-            $("#reload-notice").hidden = true;
-            $("#waiting-notice").hidden = false;
-          }
-          yield ShadersEditorsView.setText({ vs: "", fs: "" });
-          $("#content").hidden = true;
-        }).then(() => window.emit(EVENTS.UI_RESET));
         break;
       }
       case "navigate": {
@@ -370,7 +371,7 @@ let ShadersEditorsView = {
    */
   destroy: Task.async(function*() {
     this._destroyed = true;
-    this._toggleListeners("off");
+    yield this._toggleListeners("off");
     for (let p of this._editorPromises.values()) {
       let editor = yield p;
       editor.destroy();
@@ -414,9 +415,6 @@ let ShadersEditorsView = {
    *        Returns a promise that resolves to an editor instance
    */
   _getEditor: function(type) {
-    if ($("#content").hidden) {
-      return promise.reject(new Error("Shader Editor is still waiting for a WebGL context to be created."));
-    }
     if (this._editorPromises.has(type)) {
       return this._editorPromises.get(type);
     }
diff --git a/browser/devtools/shadereditor/test/browser_se_aaa_run_first_leaktest.js b/browser/devtools/shadereditor/test/browser_se_aaa_run_first_leaktest.js
index bfec65b208f5..5e2f3bd191f6 100644
--- a/browser/devtools/shadereditor/test/browser_se_aaa_run_first_leaktest.js
+++ b/browser/devtools/shadereditor/test/browser_se_aaa_run_first_leaktest.js
@@ -1,13 +1,6 @@
 /* Any copyright is dedicated to the Public Domain.
    http://creativecommons.org/publicdomain/zero/1.0/ */
 
-///////////////////
-//
-// Whitelisting this test.
-// As part of bug 1077403, the leaking uncaught rejection should be fixed. 
-//
-thisTestLeaksUncaughtRejectionsAndShouldBeFixed("Error: Shader Editor is still waiting for a WebGL context to be created.");
-
 /**
  * Tests if the shader editor leaks on initialization and sudden destruction.
  * You can also use this initialization format as a template for other tests.
diff --git a/browser/devtools/shadereditor/test/browser_se_editors-contents.js b/browser/devtools/shadereditor/test/browser_se_editors-contents.js
index f6705dcb62f4..b3f85f8c079c 100644
--- a/browser/devtools/shadereditor/test/browser_se_editors-contents.js
+++ b/browser/devtools/shadereditor/test/browser_se_editors-contents.js
@@ -1,13 +1,6 @@
 /* Any copyright is dedicated to the Public Domain.
    http://creativecommons.org/publicdomain/zero/1.0/ */
 
-///////////////////
-//
-// Whitelisting this test.
-// As part of bug 1077403, the leaking uncaught rejection should be fixed. 
-//
-thisTestLeaksUncaughtRejectionsAndShouldBeFixed("Error: Shader Editor is still waiting for a WebGL context to be created.");
-
 /**
  * Tests if the editors contain the correct text when a program
  * becomes available.
diff --git a/browser/devtools/shadereditor/test/browser_se_editors-error-gutter.js b/browser/devtools/shadereditor/test/browser_se_editors-error-gutter.js
index 6129bdb66b6a..8f8c2b4d6349 100644
--- a/browser/devtools/shadereditor/test/browser_se_editors-error-gutter.js
+++ b/browser/devtools/shadereditor/test/browser_se_editors-error-gutter.js
@@ -1,13 +1,6 @@
 /* Any copyright is dedicated to the Public Domain.
    http://creativecommons.org/publicdomain/zero/1.0/ */
 
-///////////////////
-//
-// Whitelisting this test.
-// As part of bug 1077403, the leaking uncaught rejection should be fixed. 
-//
-thisTestLeaksUncaughtRejectionsAndShouldBeFixed("Error: Shader Editor is still waiting for a WebGL context to be created.");
-
 /**
  * Tests if error indicators are shown in the editor's gutter and text area
  * when there's a shader compilation error.
diff --git a/browser/devtools/shadereditor/test/browser_se_editors-error-tooltip.js b/browser/devtools/shadereditor/test/browser_se_editors-error-tooltip.js
index 6605ef06ba38..5bdc0d800e96 100644
--- a/browser/devtools/shadereditor/test/browser_se_editors-error-tooltip.js
+++ b/browser/devtools/shadereditor/test/browser_se_editors-error-tooltip.js
@@ -1,13 +1,6 @@
 /* Any copyright is dedicated to the Public Domain.
    http://creativecommons.org/publicdomain/zero/1.0/ */
 
-///////////////////
-//
-// Whitelisting this test.
-// As part of bug 1077403, the leaking uncaught rejection should be fixed. 
-//
-thisTestLeaksUncaughtRejectionsAndShouldBeFixed("Error: Shader Editor is still waiting for a WebGL context to be created.");
-
 /**
  * Tests if error tooltips can be opened from the editor's gutter when there's
  * a shader compilation error.
diff --git a/browser/devtools/shadereditor/test/browser_se_editors-lazy-init.js b/browser/devtools/shadereditor/test/browser_se_editors-lazy-init.js
index 6b7b0eb4b253..4f31ac6f572e 100644
--- a/browser/devtools/shadereditor/test/browser_se_editors-lazy-init.js
+++ b/browser/devtools/shadereditor/test/browser_se_editors-lazy-init.js
@@ -1,13 +1,6 @@
 /* Any copyright is dedicated to the Public Domain.
    http://creativecommons.org/publicdomain/zero/1.0/ */
 
-///////////////////
-//
-// Whitelisting this test.
-// As part of bug 1077403, the leaking uncaught rejection should be fixed. 
-//
-thisTestLeaksUncaughtRejectionsAndShouldBeFixed("Error: Shader Editor is still waiting for a WebGL context to be created.");
-
 /**
  * Tests if source editors are lazily initialized.
  */
@@ -16,20 +9,6 @@ function ifWebGLSupported() {
   let { target, panel } = yield initShaderEditor(SIMPLE_CANVAS_URL);
   let { gFront, ShadersEditorsView } = panel.panelWin;
 
-  try {
-    yield ShadersEditorsView._getEditor("vs");
-    ok(false, "The promise for a vertex shader editor should be rejected.");
-  } catch (e) {
-    ok(true, "The vertex shader editors wasn't initialized.");
-  }
-
-  try {
-    yield ShadersEditorsView._getEditor("fs");
-    ok(false, "The promise for a fragment shader editor should be rejected.");
-  } catch (e) {
-    ok(true, "The fragment shader editors wasn't initialized.");
-  }
-
   reload(target);
   yield once(gFront, "program-linked");
 
diff --git a/browser/devtools/shadereditor/test/browser_se_first-run.js b/browser/devtools/shadereditor/test/browser_se_first-run.js
index 4ea0ed76e687..bc02546dee8c 100644
--- a/browser/devtools/shadereditor/test/browser_se_first-run.js
+++ b/browser/devtools/shadereditor/test/browser_se_first-run.js
@@ -1,13 +1,6 @@
 /* Any copyright is dedicated to the Public Domain.
    http://creativecommons.org/publicdomain/zero/1.0/ */
 
-///////////////////
-//
-// Whitelisting this test.
-// As part of bug 1077403, the leaking uncaught rejection should be fixed. 
-//
-thisTestLeaksUncaughtRejectionsAndShouldBeFixed("Error: Shader Editor is still waiting for a WebGL context to be created.");
-
 /**
  * Tests if the shader editor shows the appropriate UI when opened.
  */
diff --git a/browser/devtools/shadereditor/test/browser_se_navigation.js b/browser/devtools/shadereditor/test/browser_se_navigation.js
index eacdb546b5c1..5336744c9f0e 100644
--- a/browser/devtools/shadereditor/test/browser_se_navigation.js
+++ b/browser/devtools/shadereditor/test/browser_se_navigation.js
@@ -1,13 +1,6 @@
 /* Any copyright is dedicated to the Public Domain.
    http://creativecommons.org/publicdomain/zero/1.0/ */
 
-///////////////////
-//
-// Whitelisting this test.
-// As part of bug 1077403, the leaking uncaught rejection should be fixed. 
-//
-thisTestLeaksUncaughtRejectionsAndShouldBeFixed("Error: Shader Editor is still waiting for a WebGL context to be created.");
-
 /**
  * Tests target navigations are handled correctly in the UI.
  */
@@ -48,8 +41,7 @@ function ifWebGLSupported() {
   let navigated = once(target, "will-navigate");
   navigate(target, "about:blank");
 
-  yield navigating;
-  yield once(panel.panelWin, EVENTS.UI_RESET);
+  yield promise.all([navigating, once(panel.panelWin, EVENTS.UI_RESET) ]);
 
   is($("#reload-notice").hidden, true,
     "The 'reload this page' notice should be hidden while navigating.");
@@ -65,18 +57,6 @@ function ifWebGLSupported() {
   is(ShadersListView.selectedIndex, -1,
     "The shaders list has a negative index.");
 
-  yield ShadersEditorsView._getEditor("vs").then(() => {
-    ok(false, "The promise for a vertex shader editor should be rejected.");
-  }, () => {
-    ok(true, "The vertex shader editors wasn't initialized.");
-  });
-
-  yield ShadersEditorsView._getEditor("fs").then(() => {
-    ok(false, "The promise for a fragment shader editor should be rejected.");
-  }, () => {
-    ok(true, "The fragment shader editors wasn't initialized.");
-  });
-
   yield navigated;
 
   is($("#reload-notice").hidden, true,
diff --git a/browser/devtools/shadereditor/test/browser_se_programs-blackbox-01.js b/browser/devtools/shadereditor/test/browser_se_programs-blackbox-01.js
index 23df460d9dc1..4cdfed7ccb30 100644
--- a/browser/devtools/shadereditor/test/browser_se_programs-blackbox-01.js
+++ b/browser/devtools/shadereditor/test/browser_se_programs-blackbox-01.js
@@ -1,13 +1,6 @@
 /* Any copyright is dedicated to the Public Domain.
    http://creativecommons.org/publicdomain/zero/1.0/ */
 
-///////////////////
-//
-// Whitelisting this test.
-// As part of bug 1077403, the leaking uncaught rejection should be fixed. 
-//
-thisTestLeaksUncaughtRejectionsAndShouldBeFixed("Error: Shader Editor is still waiting for a WebGL context to be created.");
-
 /**
  * Tests if blackboxing a program works properly.
  */
diff --git a/browser/devtools/shadereditor/test/browser_se_programs-blackbox-02.js b/browser/devtools/shadereditor/test/browser_se_programs-blackbox-02.js
index 2f3eb122472a..c2fdd38ee399 100644
--- a/browser/devtools/shadereditor/test/browser_se_programs-blackbox-02.js
+++ b/browser/devtools/shadereditor/test/browser_se_programs-blackbox-02.js
@@ -1,13 +1,6 @@
 /* Any copyright is dedicated to the Public Domain.
    http://creativecommons.org/publicdomain/zero/1.0/ */
 
-///////////////////
-//
-// Whitelisting this test.
-// As part of bug 1077403, the leaking uncaught rejection should be fixed. 
-//
-thisTestLeaksUncaughtRejectionsAndShouldBeFixed("Error: Shader Editor is still waiting for a WebGL context to be created.");
-
 /**
  * Tests if blackboxing a program works properly in tandem with blended
  * overlapping geometry.
diff --git a/browser/devtools/shadereditor/test/browser_se_programs-list.js b/browser/devtools/shadereditor/test/browser_se_programs-list.js
index 3d676a6ee1cc..5900a8e3a165 100644
--- a/browser/devtools/shadereditor/test/browser_se_programs-list.js
+++ b/browser/devtools/shadereditor/test/browser_se_programs-list.js
@@ -1,13 +1,6 @@
 /* Any copyright is dedicated to the Public Domain.
    http://creativecommons.org/publicdomain/zero/1.0/ */
 
-///////////////////
-//
-// Whitelisting this test.
-// As part of bug 1077403, the leaking uncaught rejection should be fixed. 
-//
-thisTestLeaksUncaughtRejectionsAndShouldBeFixed("Error: Shader Editor is still waiting for a WebGL context to be created.");
-
 /**
  * Tests if the programs list contains an entry after vertex and fragment
  * shaders are linked.
diff --git a/browser/devtools/shadereditor/test/browser_se_shaders-edit-01.js b/browser/devtools/shadereditor/test/browser_se_shaders-edit-01.js
index 25244322f789..c7e932c98f99 100644
--- a/browser/devtools/shadereditor/test/browser_se_shaders-edit-01.js
+++ b/browser/devtools/shadereditor/test/browser_se_shaders-edit-01.js
@@ -1,13 +1,6 @@
 /* Any copyright is dedicated to the Public Domain.
    http://creativecommons.org/publicdomain/zero/1.0/ */
 
-///////////////////
-//
-// Whitelisting this test.
-// As part of bug 1077403, the leaking uncaught rejection should be fixed. 
-//
-thisTestLeaksUncaughtRejectionsAndShouldBeFixed("Error: Shader Editor is still waiting for a WebGL context to be created.");
-
 /**
  * Tests if editing a vertex and a fragment shader works properly.
  */
diff --git a/browser/devtools/shadereditor/test/browser_se_shaders-edit-02.js b/browser/devtools/shadereditor/test/browser_se_shaders-edit-02.js
index 1deff7aa1d3e..0b6aaf0f98c0 100644
--- a/browser/devtools/shadereditor/test/browser_se_shaders-edit-02.js
+++ b/browser/devtools/shadereditor/test/browser_se_shaders-edit-02.js
@@ -1,13 +1,6 @@
 /* Any copyright is dedicated to the Public Domain.
    http://creativecommons.org/publicdomain/zero/1.0/ */
 
-///////////////////
-//
-// Whitelisting this test.
-// As part of bug 1077403, the leaking uncaught rejection should be fixed.
-//
-thisTestLeaksUncaughtRejectionsAndShouldBeFixed("Error: Shader Editor is still waiting for a WebGL context to be created.");
-
 /**
  * Tests if compile or linkage errors are emitted when a shader source
  * gets malformed after being edited.
diff --git a/browser/devtools/shadereditor/test/browser_se_shaders-edit-03.js b/browser/devtools/shadereditor/test/browser_se_shaders-edit-03.js
index 15c1b6ab8f94..a73afed6c4ea 100644
--- a/browser/devtools/shadereditor/test/browser_se_shaders-edit-03.js
+++ b/browser/devtools/shadereditor/test/browser_se_shaders-edit-03.js
@@ -1,13 +1,6 @@
 /* Any copyright is dedicated to the Public Domain.
    http://creativecommons.org/publicdomain/zero/1.0/ */
 
-///////////////////
-//
-// Whitelisting this test.
-// As part of bug 1077403, the leaking uncaught rejection should be fixed. 
-//
-thisTestLeaksUncaughtRejectionsAndShouldBeFixed("Error: Shader Editor is still waiting for a WebGL context to be created.");
-
 /**
  * Tests if editing a vertex and a fragment shader would permanently store
  * their new source on the backend and reshow it in the frontend when required.