Remove guest icon and update screen text according to new approved UI.

chrome/app/generated_resources.grd

Index: chrome/app/generated_resources.grd
diff --git a/chrome/app/generated_resources.grd b/chrome/app/generated_resources.grd
index 0f8819713f7bafe19b26099091355ccaefb8f139..38e85129ea4a38b28597e536110bcee767692a0c 100644
--- a/chrome/app/generated_resources.grd
+++ b/chrome/app/generated_resources.grd
@@ -10701,12 +10701,22 @@ Would you like to start <ph name="CONTROL_PANEL_APPLET_NAME">$1<ex>Add/Remove Pr
         </message>
       </if>
       <if expr="not is_android">
-        <message name="IDS_NEW_TAB_GUEST_SESSION_MESSAGE"
-            desc="Used when a person enters Guest Session">
-            <ph name="BEGIN_BOLD">&lt;strong&gt;</ph>You're browsing as a Guest<ph name="END_BOLD">&lt;/strong&gt;</ph>. Pages you view in this window won't appear in the browser history or search history, and they won't leave other traces, like cookies, on the computer after you sign out. Files you download and bookmarks you create won't be preserved.
-          <ph name="LINE_BREAK">&lt;br /&gt;&lt;br /&gt;<ex>&lt;br /&gt;&lt;br /&gt;</ex></ph>
-          <ph name="BEGIN_LINK">&lt;a href="$1"&gt;</ph>Learn more<ph name="END_LINK">&lt;/a&gt;<ex>&lt;/a&gt;</ex></ph> about Guest browsing.
-        </message>
+        <if expr="pp_ifdef('chromeos')">
+          <message name="IDS_NEW_TAB_GUEST_SESSION_MESSAGE"
+              desc="Used when a person enters Guest Session">
+              <ph name="BEGIN_BOLD">&lt;strong&gt;</ph>You're browsing as a Guest<ph name="END_BOLD">&lt;/strong&gt;</ph>. Pages you view in this window won't appear in the browser history and they won't leave other traces, like cookies, on the computer after you sign out. Files you download and bookmarks you create won't be preserved.
+            <ph name="LINE_BREAK">&lt;br /&gt;&lt;br /&gt;<ex>&lt;br /&gt;&lt;br /&gt;</ex></ph>
+            <ph name="BEGIN_LINK">&lt;a href="$1"&gt;</ph>Learn more<ph name="END_LINK">&lt;/a&gt;<ex>&lt;/a&gt;</ex></ph> about Guest browsing.
+          </message>
+        </if>
+        <if expr="not pp_ifdef('chromeos')">

[Evan Stade, 2013/09/05 17:08:30]

can you narrow the cope of the if expr to only the part that actually differs

[Evan Stade, 2013/09/05 17:09:29]

(I'm not actually sure if that's possible)

[bcwhite, 2013/09/05 20:07:00]

Hmmm...  I'll give it a try, but I'm not sure if that wouldn't just cause
potential issues down the road as the separate projects updated their skins.

+          <message name="IDS_NEW_TAB_GUEST_SESSION_MESSAGE"
+              desc="Used when a person enters Guest Session">
+              <ph name="BEGIN_BOLD">&lt;strong&gt;</ph>You're browsing as a Guest<ph name="END_BOLD">&lt;/strong&gt;</ph>. Pages you view in this window won't appear in the browser history and they won't leave other traces, like cookies, on the computer after you close all open Guest windows. Any files you download will be preserved, however.
+            <ph name="LINE_BREAK">&lt;br /&gt;&lt;br /&gt;<ex>&lt;br /&gt;&lt;br /&gt;</ex></ph>
+            <ph name="BEGIN_LINK">&lt;a href="$1"&gt;</ph>Learn more<ph name="END_LINK">&lt;/a&gt;<ex>&lt;/a&gt;</ex></ph> about Guest browsing.
+          </message>
+        </if>
       </if>
       <message name="IDS_NEW_TAB_RECENTLY_CLOSED_WINDOW_SINGLE"
                desc="Title of recently closed windows in the recently closed section of the new tab page when the window has a single tab">