Componentize error pages strings

As a step toward componentizing the LocalizedError class for clean
integration on iOS, this CL componentizes error pages strings.

BUG=523362

Review URL: https://codereview.chromium.org/1467193003

Cr-Commit-Position: refs/heads/master@{#362970}
diff --git a/components/components_chromium_strings.grd b/components/components_chromium_strings.grd
index b78ef6f..9206b036 100644
--- a/components/components_chromium_strings.grd
+++ b/components/components_chromium_strings.grd
@@ -154,6 +154,56 @@
         </message>
       </if>
 
+      <if expr="not is_android and not is_ios">
+        <message name="IDS_ERRORPAGES_SUMMARY_INTERNET_DISCONNECTED" desc="Summary of the error page when the network connection failed. May be followed by platform dependent instructions.">
+          Chromium can't display the webpage because your computer isn't 
+          connected to the Internet.
+        </message>
+      </if>
+
+      <message name="IDS_ERRORPAGES_SUGGESTION_FIREWALL_CONFIG_HEADER" desc="When a webpage fails to load, in some cases we suggest reconfiguring the firewall.  This is a header above some details.">
+        Allow Chromium to access the network in your firewall or antivirus
+        settings.
+      </message>
+
+      <if expr="is_macosx">
+        <message name="IDS_ERRORPAGES_SUGGESTION_PROXY_DISABLE_PLATFORM" desc="Mac OSX instructions for disabling use of a proxy server.">
+          Go to
+          Applications &gt; System Preferences &gt; Network &gt; Advanced &gt; Proxies
+          and deselect any proxies that have been selected.
+        </message>
+      </if>
+      <if expr="is_android or is_ios">
+        <message name="IDS_ERRORPAGES_SUGGESTION_PROXY_DISABLE_PLATFORM" desc="Instructions for disabling use of a proxy server (leave empty for Android and iOS).">
+        </message>
+      </if>
+      <if expr="not chromeos and is_posix and not is_macosx and not is_android and not is_ios">
+        <message name="IDS_ERRORPAGES_SUGGESTION_PROXY_DISABLE_PLATFORM" desc="Linux instructions for disabling use of a proxy server.">
+          Go to
+          the Chromium menu &gt;
+          <ph name="SETTINGS_TITLE">&lt;span jscontent="settingsTitle"&gt;&lt;/span&gt;<ex>Settings</ex></ph>
+          &gt;
+          <ph name="ADVANCED_TITLE">&lt;span jscontent="advancedTitle"&gt;&lt;/span&gt;<ex>Under the Hood</ex></ph>
+          &gt;
+          <ph name="PROXIES_TITLE">&lt;span jscontent="proxyTitle"&gt;&lt;/span&gt;<ex>Change proxy settings...</ex></ph>
+          and make sure your configuration is set to &quot;no proxy&quot; or &quot;direct.&quot;
+        </message>
+      </if>
+      <if expr="is_win">
+        <message name="IDS_ERRORPAGES_SUGGESTION_PROXY_DISABLE_PLATFORM" desc="Windows instructions for disabling use of a proxy server.">
+          Go to
+          the Chromium menu &gt;
+          <ph name="SETTINGS_TITLE">&lt;span jscontent="settingsTitle"&gt;&lt;/span&gt;<ex>Settings</ex></ph>
+          &gt;
+          <ph name="ADVANCED_TITLE">&lt;span jscontent="advancedTitle"&gt;&lt;/span&gt;<ex>Under the Hood</ex></ph>
+          &gt;
+          <ph name="PROXIES_TITLE">&lt;span jscontent="proxyTitle"&gt;&lt;/span&gt;<ex>Change proxy settings...</ex></ph>
+          &gt;
+          LAN Settings
+          and deselect the &quot;Use a proxy server for your LAN&quot; checkbox.
+        </message>
+      </if>
+
       <!-- About Flags UI -->
       <if expr="not chromeos">
         <message name="IDS_FLAGS_UI_RELAUNCH_NOTICE" desc="Notifies the user that he needs to relaunch Chromium. Shown next to a button that says 'Relaunch Now'.">