GWP-ASan: Send fewer metrics

Don't send metrics for unrelated crashes, only for GWP-ASan crashes and
error reports. The unrelated crashes are uninteresting and obscure the
other (smaller) numbers of reports that I am interested in.

Bug: 896019
Change-Id: Ic205f5fb0798b489889c2fa639fc2464f066bb6b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1518755
Commit-Queue: Vlad Tsyrklevich <vtsyrklevich@chromium.org>
Auto-Submit: Vlad Tsyrklevich <vtsyrklevich@chromium.org>
Reviewed-by: Vitaly Buka <vitalybuka@chromium.org>
Cr-Commit-Position: refs/heads/master@{#641017}

components/gwp_asan/crash_handler/crash_handler.cc

@@ -80,8 +80,8 @@ std::unique_ptr<crashpad::MinidumpUserExtensionStreamDataSource>
 HandleException(const crashpad::ProcessSnapshot& snapshot) {
   gwp_asan::Crash proto;
   auto result = CrashAnalyzer::GetExceptionInfo(snapshot, &proto);
-  UMA_HISTOGRAM_ENUMERATION("GwpAsan.CrashAnalysisResult", result);
-
+  if (result != GwpAsanCrashAnalysisResult::kUnrelatedCrash)
+    UMA_HISTOGRAM_ENUMERATION("GwpAsan.CrashAnalysisResult", result);
   if (result != GwpAsanCrashAnalysisResult::kGwpAsanCrash)
     return nullptr;