Use PageManager in About page

chrome/browser/resources/help/help_content.html

Index: chrome/browser/resources/help/help_content.html
diff --git a/chrome/browser/resources/help/help_content.html b/chrome/browser/resources/help/help_content.html
new file mode 100644
index 0000000000000000000000000000000000000000..b8054253c087a5f9fc35cee302870cbf805df812
--- /dev/null
+++ b/chrome/browser/resources/help/help_content.html
@@ -0,0 +1,113 @@
+ <div class="content-area">
+  <div id="about-container">
+    <img src="chrome://theme/IDR_PRODUCT_LOGO_32">
+    <div id="product-description">
+      <h2 i18n-content="aboutProductTitle"></h2>
+      <span i18n-content="aboutProductDescription"></span>
+    </div>
+  </div>
+  <div id="help-container">
+    <button id="get-help" i18n-content="getHelpWithChrome"></button>
+<if expr="_google_chrome">
+    <button id="report-issue" i18n-content="reportAnIssue"></button>
+</if>
+  </div>
+  <div id="version-container">
+    <div i18n-content="browserVersion" dir="ltr"></div>
+<if expr="chromeos">
+    <div>
+      <span i18n-content="platform"></span>&nbsp;<span id="os-version"></span>
+    </div>
+    <div>
+      <span i18n-content="firmware"></span>&nbsp;<span id="firmware"></span>
+    </div>
+</if>
+<if expr="chromeos or _google_chrome or is_linux">
+    <div id="update-status-container" hidden>
+      <div id="update-status-icon" class="help-page-icon up-to-date"></div>
+      <div id="update-status-message-container">
+        <div id="update-status-message" i18n-content="updateCheckStarted">
+        </div>
+<if expr="is_macosx">
+        <div id="update-obsolete-system-container" hidden>
+          <span id="update-obsolete-system"
+              i18n-content="updateObsoleteSystem"></span>
+          <a i18n-values="href:updateObsoleteSystemURL"
+              i18n-content="learnMore" target="_blank"></a>
+        </div>
+</if>
+        <div id="allowed-connection-types-message" hidden></div>
+      </div>
+    </div>
+    <div id="update-buttons-container">
+      <div id="update-percentage" hidden></div>
+<if expr="is_macosx">
+      <button id="promote" i18n-content="promote" hidden></button>
+</if>
+      <button id="relaunch" i18n-content="relaunch" hidden></button>
+<if expr="chromeos">
+      <button id="relaunch-and-powerwash"
+          i18n-content="relaunchAndPowerwash" hidden>
+      </button>
+</if>
+    </div>
+</if>
+<if expr="chromeos">
+    <div id="more-info-container">
+      <section id="channel-changer-container" hidden>
+        <h3 i18n-content="channel"></h3>
+        <select id="channel-changer">
+          <option value="stable-channel" i18n-content="stable"></option>
+          <option value="beta-channel" i18n-content="beta"></option>
+          <option value="dev-channel" i18n-content="dev"></option>
+        </select>
+        <div id="channel-change-confirmation" hidden></div>
+      </section>
+      <section id="channel-change-page-container" hidden>
+        <h3 i18n-content="channel"></h3>
+        <div id="current-channel"></div>
+        <button id="change-channel"
+            i18n-content="channelChangeButton" disabled>
+        </button>
+        <div id="channel-change-disallowed-icon"
+            class="help-page-icon" hidden>
+        </div>
+      </section>
+      <section>
+        <h3 i18n-content="webkit"></h3>
+        <div i18n-content="webkitVersion" dir="ltr"></div>
+      </section>
+      <section>
+        <h3 i18n-content="jsEngine" dir="ltr"></h3>
+        <div i18n-content="jsEngineVersion"></div>
+      </section>
+      <section>
+        <h3 i18n-content="userAgent"></h3>
+        <div i18n-content="userAgentInfo" dir="ltr"></div>
+      </section>
+      <section>
+        <h3 i18n-content="commandLine"></h3>
+        <div i18n-content="commandLineInfo" dir="ltr"></div>
+      </section>
+      <section id="build-date-container" class="empty">
+        <h3 i18n-content="buildDate"></h3>
+        <div id="build-date"></div>
+      </section>
+    </div>
+    <button id="more-info-expander" class="link-button"
+        i18n-content="showMoreInfo">
+    </button>
+</if>
+  </div>
+  <div id="product-container">
+    <div i18n-content="productName"></div>
+    <div i18n-content="productCopyright"></div>
+    <div id="product-license"></div>
+<if expr="chromeos">
+    <div id="product-os-license"></div>
+</if>
+<if expr="_google_chrome">
+    <div id="product-tos"></div>
+</if>
+  </div>
+</div>