DevTools: support live coverage

third_party/WebKit/Source/devtools/front_end/text_editor/cmdevtools.css

 .CodeMirror {
     line-height: 1.2em !important;
     background-color: transparent !important;
     color: #222;
 }
 
 .CodeMirror-linewidget {
     overflow: visible !important;
 }
 
@@ skipping 346 matching lines @@
 .CodeMirror .text-editor-coverage-unused-marker {
     text-align: right;
     padding-right: 2px;
     background-color: #E57373;
 }
 
 .CodeMirror .text-editor-coverage-unused-marker::after {
     content: " ";
 }
 
-.CodeMirror .text-editor-coverage-used-marker,
-.CodeMirror .text-editor-coverage-mixed-marker {
+.CodeMirror .text-editor-coverage-used-marker {
     text-align: right;
     padding-right: 2px;
     background-color: #81C784;
 }
 
 .CodeMirror .text-editor-coverage-used-marker::after {
     content: " ";
 }
 
-.CodeMirror .text-editor-coverage-mixed-marker::after {
-    content: " ";
-}
-
 .CodeMirror .text-editor-line-decoration {
     position: absolute;
 }
 
 .CodeMirror .text-editor-line-decoration-wave {
     position: absolute;
     top: -2px;
     right: -4px;
     left: 4px;
     cursor: pointer;
@@ skipping 70 matching lines @@
 
 .CodeMirror .auto-complete-text {
     color: rgb(128,128,128);
 }
 
 /** Prevent the codemirror textarea from stealing PageUp events **/
 .CodeMirror textarea {
     resize: none;
     overflow: hidden;
 }