Add message and Help Center link to the chooser UI

chrome/common/url_constants.cc

Index: chrome/common/url_constants.cc
diff --git a/chrome/common/url_constants.cc b/chrome/common/url_constants.cc
index 71e6bd4f8c4b7daa798215d7ca0311f10247f560..fb109a06b1d5b88ad52df9ddfd4af35195599789 100644
--- a/chrome/common/url_constants.cc
+++ b/chrome/common/url_constants.cc
@@ -760,4 +760,10 @@ const char kWindowsXPVistaDeprecationURL[] =
     "https://support.google.com/chrome/answer/95346";
 #endif
 
+const char kWebBluetoothHelpCenterURL[] =

[ortuno, 2016/02/17 16:02:59]

Would you mind changing this to "kChooserBluetoothOverviewURL"? We have many
links in our android chooser so it would help if the names are more specific.

[juncai, 2016/02/17 22:40:40]

Done.

+    "https://support.google.com/chrome?p=bluetooth";
+
+// TODO(juncai): Change to a WebUsb help center URL when one is available.

[palmer, 2016/02/17 02:19:53]

Attach a specific bug ID to this TODO. We definitely wouldn't want to ship to
stable and still be pointing to this generic help page.

[juncai, 2016/02/17 22:40:40]

Done.

+const char kWebUsbHelpCenterURL[] = "https://support.google.com";
+
 }  // namespace chrome