Fix regression in inspector breakpoints.

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

 .CodeMirror {
     line-height: 1.2em !important;
     background-color: transparent !important;
 }
 
 .CodeMirror-linewidget {
     overflow: visible !important;
 }
 
 .CodeMirror-gutter-performance {
@@ skipping 71 matching lines @@
     line-height: 12px !important;
     border-style: solid;
 }
 
 .cm-line-without-source-mapping {
     background-color: #fafafa;
 }
 
 .cm-breakpoint.cm-breakpoint-conditional .CodeMirror-linenumber {
     -webkit-border-image: url(Images/breakpointConditional.png) 1 4 1 1;
+    border-style: solid;

[lushnikov, 2016/03/24 04:05:57]

no need for this - it's basically slightly more specific selector then the one
defined at line 74.

 }
 
 @media (-webkit-min-device-pixel-ratio: 1.5) {
 .cm-breakpoint .CodeMirror-linenumber {
     -webkit-border-image: url(Images/breakpoint_2x.png) 2 8 2 2;
+    border-style: solid;

[lushnikov, 2016/03/24 04:05:58]

ditto

 }
 .cm-breakpoint.cm-breakpoint-conditional .CodeMirror-linenumber {
     -webkit-border-image: url(Images/breakpointConditional_2x.png) 2 8 2 2;
+    border-style: solid;

[lushnikov, 2016/03/24 04:05:58]

ditto

 }
 } /* media */
 
 .cm-breakpoint-disabled .CodeMirror-linenumber {
     opacity: 0.5;
 }
 
 .breakpoints-deactivated .cm-breakpoint .CodeMirror-linenumber {
     opacity: 0.5;
 }
@@ skipping 235 matching lines @@
     background-color: rgba(255, 0, 0, 0.05);
 }
 
 .CodeMirror-activeline .cm-trailing-whitespace {
     background-color: transparent;
 }
 
 .-theme-with-dark-background .CodeMirror .CodeMirror-selected {
     background-color: #454545;
 }