extensions: Replace reference to 'gallery' by 'Chrome Web Store'.

BUG=none

Review URL: https://codereview.chromium.org/1001453005

Cr-Commit-Position: refs/heads/master@{#320465}

chrome/app/generated_resources.grd

@@ -4947,8 +4947,8 @@ Even if you have downloaded files from this website before, the website might ha
         <message name="IDS_EXTENSIONS_NONE_INSTALLED" desc="Text that lets the user know that no extensions are installed.">
           Boo... You have no extensions :-(
         </message>
-        <message name="IDS_EXTENSIONS_NONE_INSTALLED_SUGGEST_GALLERY" desc="Text on next line after IDS_EXTENSIONS_NONE_INSTALLED that suggests the user look in the gallery for extensions to install.">
-          Want to <ph name="BEGIN_LINK">&lt;a target="_blank" href="$1"&gt;</ph>browse the gallery<ph name="END_LINK">&lt;/a&gt;<ex>&lt;/a&gt;</ex></ph> instead?
+        <message name="IDS_EXTENSIONS_NONE_INSTALLED_SUGGEST_GALLERY" desc="Text on next line after IDS_EXTENSIONS_NONE_INSTALLED that suggests the user look in the Chrome Web Store for extensions to install.">
+          Want to <ph name="BEGIN_LINK">&lt;a target="_blank" href="$1"&gt;</ph>browse the Chrome Web Store<ph name="END_LINK">&lt;/a&gt;<ex>&lt;/a&gt;</ex></ph> instead?
         </message>
         <message name="IDS_EXTENSIONS_INSTALL_DROP_TARGET" desc="Text on drop target for installing extensions.">
           Drop to install