bug #11529 [WebProfilerBundle] Fixed double height of canvas (hason)

This PR was merged into the 2.3 branch.

Discussion
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[WebProfilerBundle] Fixed double height of canvas

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #7065
| License       | MIT
| Doc PR        | -

Commits
-------

c689186 [WebProfilerBundle] Fixed double height of canvas

src/Symfony/Bundle/WebProfilerBundle/Resources/views/Collector/time.html.twig

@@ -193,7 +193,6 @@
                     x = request.left * ratio + space, // position
                     canvas = cache.get(elementId) || cache.set(elementId, document.getElementById(elementId)),
                     ctx    = canvas.getContext("2d"),
-                    backingStoreRatio,
                     scaleRatio,
                     devicePixelRatio;
 
@@ -206,11 +205,8 @@
 
                 // For retina displays so text and boxes will be crisp
                 devicePixelRatio  = window.devicePixelRatio          == "undefined" ? 1 : window.devicePixelRatio;
-                backingStoreRatio = ctx.webkitBackingStorePixelRatio == "undefined" ? 1 : ctx.webkitBackingStorePixelRatio;
                 scaleRatio        = devicePixelRatio / 1;
 
-                canvasHeight += gapPerEvent * drawableEvents.length;
-
                 canvas.width  = width * scaleRatio;
                 canvas.height = canvasHeight * scaleRatio;
 
@@ -363,7 +359,7 @@
                 var self = this;
 
                 _requests.forEach(function(request) {
-                    self.drawOne(request, maxRequestTime, threshold, width);
+                    self.drawOne(request, _maxRequestTime, threshold, width);
                 });
             };