diff --git a/image/test/mochitest/12M-pixels-1.png b/image/test/mochitest/12M-pixels-1.png
new file mode 100644
index 00000000000..f802dd53968
Binary files /dev/null and b/image/test/mochitest/12M-pixels-1.png differ
diff --git a/image/test/mochitest/12M-pixels-2.png b/image/test/mochitest/12M-pixels-2.png
new file mode 100644
index 00000000000..a6d430442e7
Binary files /dev/null and b/image/test/mochitest/12M-pixels-2.png differ
diff --git a/image/test/mochitest/6M-pixels.png b/image/test/mochitest/6M-pixels.png
new file mode 100644
index 00000000000..c813d8b569d
Binary files /dev/null and b/image/test/mochitest/6M-pixels.png differ
diff --git a/image/test/mochitest/mochitest.ini b/image/test/mochitest/mochitest.ini
index 380c578fdd4..bce87015f88 100644
--- a/image/test/mochitest/mochitest.ini
+++ b/image/test/mochitest/mochitest.ini
@@ -1,5 +1,4 @@
 [DEFAULT]
-skip-if = buildapp == 'b2g'
 support-files =
   INT32_MIN.bmp
   animated-gif2.gif
@@ -54,10 +53,13 @@ support-files =
   short_header.gif
   source.png
   over.png
+  6M-pixels.png
+  12M-pixels-1.png
+  12M-pixels-2.png
 
 [test_ImageContentLoaded.html]
 [test_bug399925.html]
-skip-if = e10s
+skip-if = e10s || buildapp == 'b2g' #Bug 969779 - should set preference via SpecialPowers.pushPrefEnv()
 # [test_bug435296.html]
 # disabled - See bug 578591
 [test_bug466586.html]
@@ -84,3 +86,5 @@ skip-if = e10s
 [test_drawDiscardedImage.html]
 [test_error_events.html]
 [test_short_gif_header.html]
+[test_image_buffer_limit.html]
+run-if = toolkit == "gonk"
diff --git a/image/test/mochitest/test_image_buffer_limit.html b/image/test/mochitest/test_image_buffer_limit.html
new file mode 100644
index 00000000000..0a23fa0552e
--- /dev/null
+++ b/image/test/mochitest/test_image_buffer_limit.html
@@ -0,0 +1,94 @@
+<!DOCTYPE HTML>
+<html>
+<!--
+https://bugzilla.mozilla.org/show_bug.cgi?id=878577
+-->
+<head>
+  <title>Test for Bug 878577 - Hard limit of decoded image buffer size</title>
+  <script type="application/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="application/javascript" src="imgutils.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+
+<body>
+
+<!--
+  Initial setup: The default size limit is 65M
+  Step 1: Load 6M-pixels.png ok
+  Step 2: Load 12M-pixels-1.png fail
+  Step 3: Remove 6M-pixels.png and clear the decoded image
+  Step 4: Load 12M-pixels-2.png ok
+-->
+
+<script>
+
+SimpleTest.waitForExplicitFinish();
+
+function loadImage(url) {
+  info('loading ' + url);
+  var image = new Image(50,50);
+  image.src = url;
+  document.body.appendChild(image);
+  return image;
+}
+
+function fail(msg) {
+  return function() {
+    ok(false, msg);
+    SimpleTest.finish();
+  };
+}
+
+function runTest() {
+  // provide a clean setup
+  clearImageCache();
+
+  var img_6M = loadImage('6M-pixels.png');
+  img_6M.onerror = fail('unable to load 6M-pixels.png');
+  img_6M.onload = function() {
+    ok(true, 'expect success on loading a 6M-pixel image');
+
+    var img_12M = loadImage('12M-pixels-1.png');
+    img_12M.onload = fail('should fail to load due to image buffer size limit');
+    img_12M.onerror = function() {
+      ok(true, 'expect fail on loading a 12M-pixel image');
+
+      // remove image cache
+      info('discard decoded image buffer');
+      img_6M.onerror = null;
+      img_6M.src = null;
+      img_12M.onerror = null;
+      img_12M.src = null;
+      document.body.removeChild(img_6M);
+      document.body.removeChild(img_12M);
+      clearImageCache();
+
+      // Spin the event to give the image a chance to be discarded.
+      SimpleTest.executeSoon(function() {
+        var another_img_12M = loadImage('12M-pixels-2.png');
+        another_img_12M.onerror = fail('unable to load 12M-pixels-2.png');
+        another_img_12M.onload = function() {
+          ok(true, 'expect success on loading another 12M-pixel image');
+          another_img_12M.onerror = null;
+          another_img_12M.onload = null;
+          SimpleTest.finish();
+        }; // another_img_12M.onload
+      });
+
+    }; // img_12M.onerror
+  }; // img_6M.onload
+}
+
+window.addEventListener("load", function() {
+  SpecialPowers.pushPrefEnv({
+    "set": [
+      // XXX prevent displayed imgFrame been released
+      ["image.mem.allow_locking_in_content_processes", true]
+    ]
+  }, runTest);
+});
+
+</script>
+</body>
+</html>
+
