Add cross-platform API to get the form factor of the device

chrome/browser/web_resource/notification_promo.cc

Index: chrome/browser/web_resource/notification_promo.cc
diff --git a/chrome/browser/web_resource/notification_promo.cc b/chrome/browser/web_resource/notification_promo.cc
index 101643f7817cdee1906bcc8cd6bcee0746b4dc10..a474b7a24d9999a5315168e016f6b49cb5b33734 100644
--- a/chrome/browser/web_resource/notification_promo.cc
+++ b/chrome/browser/web_resource/notification_promo.cc
@@ -24,13 +24,9 @@
 #include "components/user_prefs/pref_registry_syncable.h"
 #include "content/public/browser/user_metrics.h"
 #include "net/base/url_util.h"
+#include "ui/base/device_form_factor.h"
 #include "url/gurl.h"
 
-#if defined(OS_ANDROID)
-#include "base/command_line.h"
-#include "chrome/common/chrome_switches.h"
-#endif  // defined(OS_ANDROID)
-
 using content::UserMetricsAction;
 
 namespace {
@@ -61,20 +57,20 @@ const char kPrefPromoClosed[] = "closed";
 std::string PlatformString() {
 #if defined(OS_WIN)
   return "win";
+#elif defined(OS_ANDROID)
+  ui::DeviceFormFactor form_factor = ui::GetDeviceFormFactor();
+  return std::string("android-") +
+      (form_factor == ui::DEVICE_FORM_FACTOR_TABLET ? "tablet" : "phone");
 #elif defined(OS_IOS)
-  // TODO(noyau): add iOS-specific implementation
-  const bool isTablet = false;
-  return std::string("ios-") + (isTablet ? "tablet" : "phone");
+  ui::DeviceFormFactor form_factor = ui::GetDeviceFormFactor();

[blundell, 2013/11/05 15:03:57]

noyau: Is this a safe change to make at the current time?

[noyau (Ping after 24h), 2013/11/05 15:48:03]

Probably safe. We need to check with the promo server folks that they can deal
with this and we're good to go.

[aruslan, 2013/11/05 16:35:36]

Server-wise it is safe, supported and would enable the promo on tablets.
ios-phone:
https://clients3.google.com/crsignal/client?hl=en-US&dist=stable&branding=31....
ios-tablet:
https://clients3.google.com/crsignal/client?hl=en-US&dist=stable&branding=31....

noyau@ -- if you want the promo to be disabled on iPads please let me know.

+  return std::string("ios-") +
+      (form_factor == ui::DEVICE_FORM_FACTOR_TABLET ? "tablet" : "phone");
 #elif defined(OS_MACOSX)
   return "mac";
 #elif defined(OS_CHROMEOS)
   return "chromeos";
 #elif defined(OS_LINUX)
   return "linux";
-#elif defined(OS_ANDROID)
-  const bool isTablet =
-      CommandLine::ForCurrentProcess()->HasSwitch(switches::kTabletUI);
-  return std::string("android-") + (isTablet ? "tablet" : "phone");
 #else
   return "none";
 #endif