Fix one-time version check for Mac plugin IME

chrome/browser/renderer_host/render_widget_host_view_mac.mm

Index: chrome/browser/renderer_host/render_widget_host_view_mac.mm
diff --git a/chrome/browser/renderer_host/render_widget_host_view_mac.mm b/chrome/browser/renderer_host/render_widget_host_view_mac.mm
index a7c6581c676b797071d73ee5d724f0ac43b561d1..3281a0e16c7eadaf7e84183aacf5efe840a60400 100644
--- a/chrome/browser/renderer_host/render_widget_host_view_mac.mm
+++ b/chrome/browser/renderer_host/render_widget_host_view_mac.mm
@@ -2527,6 +2527,7 @@ extern NSString *NSTextInputReplacementRangeAttributeName;
     int32 major, minor, bugfix;
     base::SysInfo::OperatingSystemVersionNumbers(&major, &minor, &bugfix);
     sImeSupported = major > 10 || (major == 10 && minor > 5);
+    sHaveCheckedSupport = YES;
   }
   if (!sImeSupported)
     return false;