Implement 'Do Not Track' header

chrome/browser/resources/options/browser_options.html

 <div id="settings" class="page" hidden>
   <header>
     <h1 i18n-content="settingsTitle"></h1>
   </header>
 <if expr="not pp_ifdef('chromeos')">
   <include src="sync_section.html">
 </if>
 <if expr="pp_ifdef('chromeos')">
   <section>
     <h3 i18n-content="sectionTitleInternet"></h3>
@@ skipping 71 matching lines @@
       <div id="touchpad-settings" class="settings-row" hidden>
         <span class="option-name" i18n-content="touchpadSpeed"></span>
         <input id="sensitivity-range" type="range" min="1" max="5"
             pref="settings.touchpad.sensitivity2" class="touch-slider">
       </div>
       <div id="mouse-settings" class="settings-row" hidden>
         <span class="option-name" i18n-content="mouseSpeed"></span>
         <input id="sensitivity-range" type="range" min="1" max="5"
             pref="settings.mouse.sensitivity2" class="touch-slider">
       </div>
-      <div id="no-pointing-devices" i18n-content="noPointingDevices" 
+      <div id="no-pointing-devices" i18n-content="noPointingDevices"
           class="settings-row" hidden>
       </div>
       <div class="settings-row">
         <button id="pointer-settings-button">
         </button>
         <button id="keyboard-settings-button"
             i18n-content="keyboardSettingsButtonTitle">
         </button>
         <!-- By default, the display settings are hidden.  They are only visible
              if more than one display is found. -->
@@ skipping 158 matching lines @@
           <input id="metricsReportingEnabled"
               pref="cros.metrics.reportingEnabled" type="checkbox">
 </if>
 <if expr="not pp_ifdef('chromeos')">
           <input id="metricsReportingEnabled" type="checkbox">
 </if>
           <span i18n-content="enableLogging"></span>
         </label>
       </div>
 </if>  <!-- pp_ifdef('_google_chrome') -->
+      <div class="checkbox">
+        <label>
+          <input id="do-not-track-enabled" pref="enable_do_not_track"
+              metric="Options_DoNotTrackCheckbox" type="checkbox">
+          <span i18n-content="doNotTrack"></span>
+        </label>
+      </div>
     </div>
   </section>
 <if expr="pp_ifdef('chromeos')">
   <!-- By default, the bluetooth section is hidden.  It is only visible if a
        bluetooth adapter is discovered -->
   <section id="bluetooth-devices" hidden>
     <h3 i18n-content="bluetooth"></h3>
     <div id="bluetooth-options-div">
       <div class="checkbox">
         <label>
@@ skipping 136 matching lines @@
         <label>
           <input type="checkbox"
               pref="download.prompt_for_download"
               metric="Options_AskForSaveLocation">
           <span i18n-content="downloadLocationAskForSaveLocation"></span>
         </label>
       </div>
 <if expr="pp_ifdef('chromeos')">
       <div class="checkbox" guest-visibility="disabled">
         <label>
-          <input type="checkbox" 
-          pref="gdata.disabled" 
-          metric="Options_DisableGData">
+          <input type="checkbox"
+              pref="gdata.disabled"
+              metric="Options_DisableGData">
           <span i18n-content="disableGData"></span>
         </label>
-      </div>  
-</if>    
+      </div>
+</if>
 <if expr="not pp_ifdef('chromeos')">
       <div id="auto-open-file-types-section" hidden>
         <div id="auto-open-file-types-container">
           <div id="auto-open-file-types-label"
               i18n-content="autoOpenFileTypesInfo"></div>
           <button id="autoOpenFileTypesResetToDefault"
               i18n-content="autoOpenFileTypesResetToDefault"></button>
         </div>
       </div>
 </if>
@@ skipping 29 matching lines @@
               i18n-content="cloudPrintConnectorEnabledManageButton"></button>
         </div>
       </div>
     </section>
 </if>
 <if expr="pp_ifdef('chromeos')">
   <section id="cloud-print-connector-section">
     <h3 i18n-content="advancedSectionTitleCloudPrint"></h3>
     <div>
       <div>
-        <span i18n-content="cloudPrintChromeosOptionLabel"></span> 
+        <span i18n-content="cloudPrintChromeosOptionLabel"></span>
         <a target="_blank" i18n-content="learnMore"
             i18n-values="href:cloudPrintLearnMoreURL"></a>
       </div>
       <div class="settings-row">
         <button id="cloudPrintManageButton"
             i18n-content="cloudPrintChromeosOptionButton"></button>
       </div>
     </div>
   </section>
 <if expr="pp_ifdef('chromeos')">
@@ skipping 41 matching lines @@
   </section>
 </if>
 </div>  <!-- advanced-settings-container -->
 </div>  <!-- advanced-settings -->
 <footer>
   <button id="advanced-settings-expander" class="link-button"
       i18n-content="showAdvancedSettings">
   </button>
 </footer>
 </div>