DevTools: [Documentation] fix css styles for renderer

BUG=391593

Review URL: https://codereview.chromium.org/554243002

git-svn-id: svn://svn.chromium.org/blink/trunk@181639 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/Source/devtools/front_end/documentation/DocumentationView.js

@@ -217,7 +217,8 @@ WebInspector.DocumentationView.Renderer.prototype = {
                 liveUrl.href = examples[i].liveUrl;
                 liveUrl.textContent = WebInspector.UIString("Example");
             }
-            exampleDescription.appendChild(this._renderBlock(examples[i].description));
+            if (examples[i].description)
+                exampleDescription.appendChild(this._renderBlock(examples[i].description));
             var code = example.createChild("div", "documentation-code");
             code.classList.add("source-code");
             code.textContent = examples[i].code;

third_party/WebKit/Source/devtools/front_end/documentationView.css

@@ -62,11 +62,12 @@
 }
 
 .documentation-example-description-section {
-    margin-bottom: 10px;
+    margin-bottom: 20px;
 }
 
 .documentation-example-link {
     float: right;
+    background-color: rgb(241, 246, 251);
 }
 
 .documentation-box {