Avoid rounding down viewport dimensions in Media Queries

third_party/WebKit/LayoutTests/fast/media/mq-width-on-zoom.html

Index: third_party/WebKit/LayoutTests/fast/media/mq-width-on-zoom.html
diff --git a/third_party/WebKit/LayoutTests/fast/media/mq-width-on-zoom.html b/third_party/WebKit/LayoutTests/fast/media/mq-width-on-zoom.html
index 6456ca5a06fafa1c80e9b17f395b165370719064..ad4f5e1d8b3dd70fcedd6e74dd373c5edc06845e 100644
--- a/third_party/WebKit/LayoutTests/fast/media/mq-width-on-zoom.html
+++ b/third_party/WebKit/LayoutTests/fast/media/mq-width-on-zoom.html
@@ -11,24 +11,11 @@
             // eventSender.zoomPageOut/In zooms with a fixed factor of 1.2 instead
             // of the zoom levels of the actual browser.
 
-            function printMatch(match) {
-                return (match > 0) ? "matches " + match + "px." : "doesn't match tested values.";
-            }
-
             function test() {
-                shouldBeTrue("window.matchMedia('(width: " + window.innerWidth + "px)').matches");
-                if (window.matchMedia("(width: " + window.innerWidth + "px)").matches)
-                    return;
-
-                var matches = 0
-                for (var j = 0; j < window.innerWidth + 100; j++) {
-                    if (window.matchMedia("(width: " + j + "px)").matches) {
-                        matches = j;
-                        break;
-                    }
-                }
-
-                debug("window.innerWidth is " + window.innerWidth + "px, but width MQ feature " + printMatch(j));
+                var minWidth = window.innerWidth - 1;
+                var maxWidth = window.innerWidth + 1;
+                shouldBeTrue("window.matchMedia('(min-width: " + minWidth + "px)').matches");
+                shouldBeTrue("window.matchMedia('(max-width: " + maxWidth + "px)').matches");
             }
 
             if (window.eventSender) {