Alias |ranges| so it appears in minidump.

base/metrics/histogram.cc

Index: base/metrics/histogram.cc
diff --git a/base/metrics/histogram.cc b/base/metrics/histogram.cc
index b7ef10749f86c7387f553137882474497801e311..c2eb63d8876088bc75853beb501a8656b436870d 100644
--- a/base/metrics/histogram.cc
+++ b/base/metrics/histogram.cc
@@ -118,6 +118,7 @@ class Histogram::Factory {
   virtual BucketRanges* CreateRanges() {
     BucketRanges* ranges = new BucketRanges(bucket_count_ + 1);
     Histogram::InitializeBucketRanges(minimum_, maximum_, ranges);
+    base::debug::Alias(&ranges);  // TODO(bcwhite): Remove after crbug/586622.

[brucedawson, 2017/08/17 19:28:00]

Be aware that this technique doesn't work very well. Because ranges is a pointer
all that this ensures is that the compiler won't discard the pointer before the
end of the function, which was already guaranteed by the return statement. The
Alias() function does nothing to ensure that the memory pointed to be ranges is
retained in crash dumps. And, either way, the effect of Alias() only extends to
the end of the function where it is called.

See https://chromium-review.googlesource.com/c/619112

[bcwhite, 2017/08/18 05:09:01]

Yeah...  I've noticed that.  :-(  It would be nice if it somehow gave a hint to
Crashpad and got that memory included in a dump.

     return ranges;
   }
 
@@ -780,6 +781,7 @@ class LinearHistogram::Factory : public Histogram::Factory {
   BucketRanges* CreateRanges() override {
     BucketRanges* ranges = new BucketRanges(bucket_count_ + 1);
     LinearHistogram::InitializeBucketRanges(minimum_, maximum_, ranges);
+    base::debug::Alias(&ranges);  // TODO(bcwhite): Remove after crbug/586622.
     return ranges;
   }
 
@@ -975,6 +977,7 @@ class BooleanHistogram::Factory : public Histogram::Factory {
   BucketRanges* CreateRanges() override {
     BucketRanges* ranges = new BucketRanges(3 + 1);
     LinearHistogram::InitializeBucketRanges(1, 2, ranges);
+    base::debug::Alias(&ranges);  // TODO(bcwhite): Remove after crbug/586622.
     return ranges;
   }