Use stricter type checking in UMA_HISTOGRAM_ENUMERATION

ios/chrome/today_extension/today_view_controller.mm

Index: ios/chrome/today_extension/today_view_controller.mm
diff --git a/ios/chrome/today_extension/today_view_controller.mm b/ios/chrome/today_extension/today_view_controller.mm
index eedd5c1c90edb37432ce0344a0906bcf697fc185..a1002e040f68dd9b56b3348e2519a997a6a1e891 100644
--- a/ios/chrome/today_extension/today_view_controller.mm
+++ b/ios/chrome/today_extension/today_view_controller.mm
@@ -927,8 +927,9 @@ NSString* const kPhysicalWebOptedInPreference = @"PhysicalWebOptedIn";
     state |= PHYSICAL_WEB_OPTED_IN_UNDECIDED_FLAG;
   }
   DCHECK(state < PHYSICAL_WEB_INITIAL_STATE_COUNT);
-  UMA_HISTOGRAM_ENUMERATION("PhysicalWeb.InitialState", state,
-                            PHYSICAL_WEB_INITIAL_STATE_COUNT);
+  UMA_HISTOGRAM_EXACT_LINEAR(

[Alexei Svitkine (slow), 2017/05/31 20:22:24]

Same comment as physical_web_initial_state_recorder.mm.

[wychen, 2017/07/14 23:18:44]

Used PhysicalWebInitialStateIosChrome.

+      "PhysicalWeb.InitialState", state,
+      static_cast<int>(PHYSICAL_WEB_INITIAL_STATE_COUNT));
 }
 
 - (void)scannerBluetoothStatusUpdated:(PhysicalWebScanner*)scanner {