Allow only responsive websites to install as a web app on mobile.

chrome/browser/banners/app_banner_debug_log.cc

Index: chrome/browser/banners/app_banner_debug_log.cc
diff --git a/chrome/browser/banners/app_banner_debug_log.cc b/chrome/browser/banners/app_banner_debug_log.cc
index 36818b0b6ade365ccece596be18304a58e9c7375..5ba137654fff3f195ed0f97c77b69fd77dccd4d0 100644
--- a/chrome/browser/banners/app_banner_debug_log.cc
+++ b/chrome/browser/banners/app_banner_debug_log.cc
@@ -39,12 +39,24 @@ const char kNotServedFromSecureOrigin[] =
 const char kIgnoredNotSupportedOnAndroid[] =
     " application ignored: not supported on Android";
 const char kIgnoredNoId[] = "play application ignored: no id provided";
+const char kAddMetaViewportTag[] =
+    "Please check that your site displays appropriately on mobile, and add the "
+    "meta viewport tag with content width=device-width or initial-scale=1";
+// The trailing spaces are intentional as another string is appended.
+const char kMetaViewportTagNotResponsive[] =

[benwells, 2015/05/27 05:58:55]

Why are there two strings when they are appended together?

[dominickn (DO NOT USE), 2015/06/05 07:42:59]

Done.

+    "meta viewport tag not detected, or it contains no indication that your "
+    "site scales for mobile devices. ";
 
 void OutputDeveloperNotShownMessage(content::WebContents* web_contents,
                                     const std::string& message) {
   OutputDeveloperDebugMessage(web_contents, "not shown: " + message);
 }
 
+void OutputDeveloperMetaViewportErrorMessage(content::WebContents* web_contents,
+                                             const std::string& message) {
+  OutputDeveloperNotShownMessage(web_contents, message + kAddMetaViewportTag);
+}
+
 void OutputDeveloperDebugMessage(content::WebContents* web_contents,
                                  const std::string& message) {
   std::string log_message = "App banner " + message;