Only detect outdated builds on Google Chrome.

Prior to https://crrev.com/643864, they weren't detected for Chromium on
account of the way google_brand worked. That CL changed behavior and
accidentally started showing the outdated build bubble for Linux
Chromium users.

BUG=1010592

Change-Id: I069ac36166e2ae720d58b1b9aa85605792be8684
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1841635Reviewed-by: Thomas Anderson <thomasanderson@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Greg Thompson <grt@chromium.org>
Cr-Commit-Position: refs/heads/master@{#703131}

chrome/browser/upgrade_detector/upgrade_detector_impl.cc

@@ -31,6 +31,7 @@
 #include "base/time/default_tick_clock.h"
 #include "base/time/tick_clock.h"
 #include "base/time/time.h"
+#include "build/branding_buildflags.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/google/google_brand.h"
 #include "chrome/browser/obsolete_system/obsolete_system.h"
@@ -74,6 +75,14 @@ constexpr base::TimeDelta kNotifyCycleTimeForTesting =
 // The number of days after which we identify a build/install as outdated.
 constexpr base::TimeDelta kOutdatedBuildAge = base::TimeDelta::FromDays(12 * 7);
 
+constexpr bool ShouldDetectOutdatedBuilds() {
+#if BUILDFLAG(GOOGLE_CHROME_BRANDING)
+  return true;
+#else   // BUILDFLAG(GOOGLE_CHROME_BRANDING)
+  return false;
+#endif  // BUILDFLAG(GOOGLE_CHROME_BRANDING)
+}
+
 // Return the string that was passed as a value for the
 // kCheckForUpdateIntervalSec switch.
 std::string CmdLineInterval() {
@@ -414,6 +423,9 @@ bool UpgradeDetectorImpl::DetectOutdatedInstall() {
       return false;
     }
 #endif
+
+    if (!ShouldDetectOutdatedBuilds())
+      return false;
   }
 
   base::Time network_time;