bug #9716 Reset the box model to content-box in the web debug toolbar (stof)

This PR was merged into the 2.3 branch.

Discussion
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Reset the box model to content-box in the web debug toolbar

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

This makes the styles compatible with CSS frameworks changing the box model to box-sizing using a universal selector (Bootstrap 3 for instance).

Commits
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ae95a71 Reset the box model to content-box in the web debug toolbar

src/Symfony/Bundle/WebProfilerBundle/Resources/views/Profiler/toolbar.css.twig

@@ -18,6 +18,12 @@
     z-index: 6000000;
 }
 
+.sf-toolbarreset * {
+    -webkit-box-sizing: content-box;
+    -moz-box-sizing: content-box;
+    box-sizing: content-box;
+}
+
 .sf-toolbarreset {
     position: fixed;
     background-color: #f7f7f7;