Split the Media settings UI into separate microphone and camera sections.

chrome/browser/resources/options/content_settings_exceptions_area.html

 <div id="content-settings-exceptions-area" class="page" hidden>
   <div class="close-button"></div>
   <h1></h1>
   <div class="content-area">
     <div id="exception-column-headers">
       <div id="exception-pattern-column" i18n-content="exceptionPatternHeader">
       </div>
       <div id="exception-behavior-column"
           i18n-content="exceptionBehaviorHeader"
           class="exception-value-column-header">
@@ skipping 71 matching lines @@
       </div>
     </div>
     <div contentType="protectedContent">
       <list mode="normal"></list>
       <div>
         <span class="otr-explanation" i18n-content="otrExceptionsExplanation">
         </span>
         <list mode="otr"></list>
       </div>
     </div>
-    <div id="media-column-header" class="media-header">
-      <div id="exception-pattern-column"></div>
-      <div id="media-audio-column" i18n-content=mediaAudioExceptionHeader>
-      </div>
-      <div id="media-video-column" i18n-content="mediaVideoExceptionHeader">
-      </div>
-    </div>
-    <div contentType="media-stream">
+    <div contentType="media-stream-mic">
       <list mode="normal"></list>
       <div>
         <span class="otr-explanation" i18n-content="otrExceptionsExplanation">
+        </span>
+        <list mode="otr"></list>
+      </div>
+      <div id="media-pepper-flash-exceptions" class="pepper-flash-settings">
+        <span i18n-content="mediaPepperFlashExceptionsDivergedLabel"></span>
+        <a target="_blank" i18n-content="mediaPepperFlashChangeLink"
+            i18n-values="href:mediaPepperFlashWebsitePrivacyURL"></a>
+      </div>
+    </div>
+    <div contentType="media-stream-camera">
+      <list mode="normal"></list>
+      <div>
+        <span class="otr-explanation" i18n-content="otrExceptionsExplanation">
         </span>
         <list mode="otr"></list>
       </div>
       <div id="media-pepper-flash-exceptions" class="pepper-flash-settings">
         <span i18n-content="mediaPepperFlashExceptionsDivergedLabel"></span>
         <a target="_blank" i18n-content="mediaPepperFlashChangeLink"
             i18n-values="href:mediaPepperFlashWebsitePrivacyURL"></a>
       </div>
     </div>
     <div contentType="ppapi-broker">
@@ skipping 39 matching lines @@
     </div>
     <div class="action-area-right">
       <div class="button-strip">
         <button id="content-settings-exceptions-overlay-confirm"
             class="default-button" i18n-content="done">
         </button>
       </div>
     </div>
   </div>
 </div>