diff -r 000000000000 -r 6474c204b198 mobile/android/base/tests/test_bug720538.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mobile/android/base/tests/test_bug720538.java	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,74 @@
+package org.mozilla.gecko.tests;
+
+import org.mozilla.gecko.Actions;
+import org.mozilla.gecko.PaintedSurface;
+
+public class test_bug720538 extends PixelTest {
+    public void test_bug720538() {
+        String url = getAbsoluteUrl("/robocop/test_bug720538.html");
+
+        blockForGeckoReady();
+
+        /*
+         * for this test, we load the associated test_bug720538.html file. this file has two
+         * iframes (painted completely blue - #0000FF) and the rest of the page is the background
+         * color, which is #008000 green. When we first render the page there is an iframe in
+         * the top-left corner, and when we double-tap on it it should zoom to fill the visible
+         * view area leaving a little bit of space on either side. We can test for this by checking
+         * a few pixels to ensure that there is some background visible on either side of the iframe.
+         * Finally, when we double-tap on it to zoom out again, we need to check that the bottom of
+         * the view doesn't have any checkerboarding. We can verify this by getting a few pixels and
+         * checking that it is the same as the expected background color of the page, as opposed to
+         * the gray shades of the checkerboard.
+         */
+
+        PaintedSurface painted = loadAndGetPainted(url);
+
+        try {
+            // first we check that the point we want to double-tap (100, 100) is blue, indicating it's inside the iframe
+            mAsserter.ispixel(painted.getPixelAt(100, 100), 0, 0, 0xFF, "Ensuring double-tap point is in the iframe");
+        } finally {
+            painted.close();
+        }
+
+        // do the double tap and wait for the double-tap animation to finish. we assume the animation is done
+        // when we find a 500ms period with no paint events that occurs after at least one paint event.
+        Actions.RepeatedEventExpecter paintExpecter = mActions.expectPaint();
+        MotionEventHelper meh = new MotionEventHelper(getInstrumentation(), mDriver.getGeckoLeft(), mDriver.getGeckoTop());
+        meh.doubleTap(100, 100);
+        painted = waitForPaint(paintExpecter);
+        paintExpecter.unregisterListener();
+
+        try {
+            // check a few points to ensure that we did a good zoom-to-block on the iframe. this checks that
+            // the background color is visible on the left and right edges of the viewport, but the iframe is
+            // visible in between those edges
+            mAsserter.ispixel(painted.getPixelAt(0, 100), 0, 0x80, 0, "Checking page background to the left of the iframe");
+            mAsserter.ispixel(painted.getPixelAt(50, 100), 0, 0, 0xFF, "Checking for iframe a few pixels from the left edge");
+            mAsserter.ispixel(painted.getPixelAt(mDriver.getGeckoWidth() - 51, 100), 0, 0, 0xFF, "Checking for iframe a few pixels from the right edge");
+            mAsserter.ispixel(painted.getPixelAt(mDriver.getGeckoWidth() - 1, 100), 0, 0x80, 0, "Checking page background the right of the iframe");
+        } finally {
+            painted.close();
+        }
+
+        // now we do double-tap again to zoom out and wait for the animation to finish, as before
+        paintExpecter = mActions.expectPaint();
+        meh.doubleTap(mDriver.getGeckoWidth() / 2, 100);
+        painted = waitForPaint(paintExpecter);
+        paintExpecter.unregisterListener();
+
+        try {
+            // and now we check a pixel at the bottom of the view to ensure that we have the page
+            // background and not some checkerboarding. use the second-last row of pixels instead of
+            // the last row because the last row is subject to rounding and clipping errors
+            for (int y = 2; y < 10; y++) {
+                for (int x = 0; x < 10; x++) {
+                    mAsserter.dumpLog("Pixel at " + x + ", " + (mDriver.getGeckoHeight() - y) + ": " + Integer.toHexString(painted.getPixelAt(x, mDriver.getGeckoHeight() - y)));
+                }
+            }
+            mAsserter.ispixel(painted.getPixelAt(0, mDriver.getGeckoHeight() - 2), 0, 0x80, 0, "Checking bottom-left corner of viewport");
+        } finally {
+            painted.close();
+        }
+    }
+}