Add a 32-bit/64-bit string to chrome://version.

Change created by following existing patterns and reading:
http://www.chromium.org/developers/design-documents/ui-localization

BUG=448585,381246

Review URL: https://codereview.chromium.org/811193005

Cr-Commit-Position: refs/heads/master@{#311396}

chrome/app/generated_resources.grd

@@ -7235,6 +7235,12 @@ Keep your key file in a safe place. You will need it to create new versions of y
       <message name="IDS_ABOUT_VERSION_UNOFFICIAL" desc="unofficial build on the about:version page">
         Developer Build
       </message>
+      <message name="IDS_ABOUT_VERSION_32BIT" desc="32-bit on the chrome://version page">
+        (32-bit)
+      </message>
+      <message name="IDS_ABOUT_VERSION_64BIT" desc="64-bit on the chrome://version page">
+        (64-bit)
+      </message>
       <message name="IDS_ABOUT_VERSION_REVISION" desc="label for the revision on the about:version page">
         Revision
       </message>

chrome/browser/resources/about_version.html

@@ -42,6 +42,7 @@ about:version template page
             <span i18n-content="version"></span>
             (<span i18n-content="official"></span>)
             <span i18n-content="version_modifier"></span>
+            <span i18n-content="version_bitsize"></span>
           </td>
         </tr>
         <tr>

chrome/browser/ui/webui/version_ui.cc

@@ -83,6 +83,11 @@ WebUIDataSource* CreateVersionUIDataSource() {
   html_source->AddLocalizedString("official",
       version_info.IsOfficialBuild() ? IDS_ABOUT_VERSION_OFFICIAL :
                                        IDS_ABOUT_VERSION_UNOFFICIAL);
+#if defined(ARCH_CPU_64_BITS)
+  html_source->AddLocalizedString("version_bitsize", IDS_ABOUT_VERSION_64BIT);
+#else
+  html_source->AddLocalizedString("version_bitsize", IDS_ABOUT_VERSION_32BIT);
+#endif
   html_source->AddLocalizedString("user_agent_name",
                                   IDS_ABOUT_VERSION_USER_AGENT);
   html_source->AddString("useragent", GetUserAgent());