Crash when we notice a corruption of the histogram range-vector...

chrome/common/metrics_helpers.cc

Index: chrome/common/metrics_helpers.cc
===================================================================
--- chrome/common/metrics_helpers.cc	(revision 76117)
+++ chrome/common/metrics_helpers.cc	(working copy)
@@ -531,6 +531,18 @@
   const std::string& histogram_name = histogram.histogram_name();
 
   int corruption = histogram.FindCorruption(snapshot);
+
+  // Crash if we detect that our histograms have been overwritten.  This may be
+  // a fair distance from the memory smasher, but we hope to correlate these
+  // crashes with other events, such as plugins, or usage patterns, etc.
+  if (Histogram::BUCKET_ORDER_ERROR & corruption) {
+    // The checksum should have caught this, so crash separately if it didn't.
+    CHECK_NE(0, Histogram::RANGE_CHECKSUM_ERROR & corruption);
+    CHECK(false);  // Crash for the bucket order corruption.
+  }
+  // Checksum corruption might not have caused order corruption.
+  CHECK_EQ(0, Histogram::RANGE_CHECKSUM_ERROR & corruption);
+
   if (corruption) {
     NOTREACHED();
     InconsistencyDetected(corruption);