DevTools: Trim stylesheet URLs in the Styles sidebar to 30 characters

LayoutTests/inspector/styles/inject-stylesheet-expected.txt

 CONSOLE MESSAGE: line 9: iframe loaded
 Tests that injected user stylesheets are reflected in the Styles pane.
 
 
 Main frame style:
 [expanded] 
 -webkit-background-clip: border-box;
 -webkit-background-origin: padding-box;
 -webkit-background-size: auto;
 -webkit-border-image: url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAQCAQAAAC1+jfqAAAAiElEQ…Ms+LS30CAhBN5nNxeT5hbJ1zwmji2k+aF6NENIPf/hs54f0sZFUVAMigAAAABJRU5ErkJggg==) 100% / 1 / 0px stretch;
@@ skipping 44 matching lines @@
 display: block;
 
 
 iframe style:
 [expanded] 
 -webkit-background-clip: border-box;
 -webkit-background-origin: padding-box;
 -webkit-background-size: auto;
 background-attachment: scroll;
     #iframebody - initial user stylesheet
-    /-- overloaded --/ body - initial inject-stylesheet-iframe-data.html:4
+    /-- overloaded --/ body - initial inject-styleshe…me-data.html:4
 background-clip: border-box;
     #iframebody - initial user stylesheet
-    /-- overloaded --/ body - initial inject-stylesheet-iframe-data.html:4
+    /-- overloaded --/ body - initial inject-styleshe…me-data.html:4
 background-color: rgb(255, 0, 0);
     #iframebody - red user stylesheet
-    /-- overloaded --/ body - green inject-stylesheet-iframe-data.html:4
+    /-- overloaded --/ body - green inject-styleshe…me-data.html:4
 background-image: none;
     #iframebody - initial user stylesheet
-    /-- overloaded --/ body - initial inject-stylesheet-iframe-data.html:4
+    /-- overloaded --/ body - initial inject-styleshe…me-data.html:4
 background-origin: padding-box;
     #iframebody - initial user stylesheet
-    /-- overloaded --/ body - initial inject-stylesheet-iframe-data.html:4
+    /-- overloaded --/ body - initial inject-styleshe…me-data.html:4
 background-size: auto;
     #iframebody - initial user stylesheet
-    /-- overloaded --/ body - initial inject-stylesheet-iframe-data.html:4
+    /-- overloaded --/ body - initial inject-styleshe…me-data.html:4
 display: block;
     body - block user agent stylesheet
 margin-bottom: 8px;
     body - 8px user agent stylesheet
 margin-left: 8px;
     body - 8px user agent stylesheet
 margin-right: 8px;
     body - 8px user agent stylesheet
 margin-top: 8px;
     body - 8px user agent stylesheet
@@ skipping 11 matching lines @@
     background-size: initial;
     background-repeat-x: initial;
     background-repeat-y: initial;
     background-attachment: initial;
     background-origin: initial;
     background-clip: initial;
     background-color: red;
 
 [expanded] 
 media="screen" (inject-stylesheet-iframe-data.html)
-body  { (inject-stylesheet-iframe-data.html:4 -> inject-stylesheet-iframe-data.html:4:3)
+body  { (inject-styleshe…me-data.html:4 -> inject-stylesheet-iframe-data.html:4:3)
 background: green;
     /-- overloaded --/ background-image: initial;
     /-- overloaded --/ background-position-x: initial;
     /-- overloaded --/ background-position-y: initial;
     /-- overloaded --/ background-size: initial;
     /-- overloaded --/ background-repeat-x: initial;
     /-- overloaded --/ background-repeat-y: initial;
     /-- overloaded --/ background-attachment: initial;
     /-- overloaded --/ background-origin: initial;
     /-- overloaded --/ background-clip: initial;
     /-- overloaded --/ background-color: green;
 
 [expanded] 
 body  { (user agent stylesheet)
 display: block;
 margin: 8px;
     margin-top: 8px;
     margin-right: 8px;
     margin-bottom: 8px;
     margin-left: 8px;