Revert "Fix SampleVector tests to expect CHECK rather than DCHECK deaths."

This reverts commit f0acd4fc.

Reason for revert:

Findit (https://goo.gl/kROfz5) identified CL at revision 551483 as the
culprit for failures in the build cycles as shown on:
https://findit-for-me.appspot.com/waterfall/culprit?key=ag9zfmZpbmRpdC1mb3ItbWVyRAsSDVdmU3VzcGVjdGVkQ0wiMWNocm9taXVtL2YwYWNkNGZjZjE5MzlhMTUyYzI3ODdmNjI1NjQ0YThlNTc5NDdkMjgM

Sample Failed Build: https://ci.chromium.org/buildbot/chromium.chromiumos/linux-chromeos-rel/7001

Sample Failed Step: base_unittests

Original change's description:
> Fix SampleVector tests to expect CHECK rather than DCHECK deaths.
> 
> Bug: 832728
> Change-Id: I9a2d2d330aa4d250c925b7a614780acbf40dce3f
> Reviewed-on: https://chromium-review.googlesource.com/1012732
> Reviewed-by: Alexei Svitkine <asvitkine@chromium.org>
> Commit-Queue: Wez <wez@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#551483}

Change-Id: Ie2ad7fb9ebd4c214a7dd2cebe0763b2f41793f01
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 832728
Reviewed-on: https://chromium-review.googlesource.com/1015194
Cr-Commit-Position: refs/heads/master@{#551512}

base/metrics/sample_vector_unittest.cc

@@ -143,9 +143,9 @@ TEST_F(SampleVectorTest, BucketIndexDeath) {
   EXPECT_EQ(3, samples.GetCount(65));
 
   // Extreme case.
-  EXPECT_DEATH_IF_SUPPORTED(samples.Accumulate(INT_MIN, 100), "");
-  EXPECT_DEATH_IF_SUPPORTED(samples.Accumulate(-1, 100), "");
-  EXPECT_DEATH_IF_SUPPORTED(samples.Accumulate(INT_MAX, 100), "");
+  EXPECT_DCHECK_DEATH(samples.Accumulate(INT_MIN, 100));
+  EXPECT_DCHECK_DEATH(samples.Accumulate(-1, 100));
+  EXPECT_DCHECK_DEATH(samples.Accumulate(INT_MAX, 100));
 
   // Custom buckets: [1, 5) [5, 10)
   // Note, this is not a valid BucketRanges for Histogram because it does not
@@ -165,8 +165,8 @@ TEST_F(SampleVectorTest, BucketIndexDeath) {
   EXPECT_EQ(4, samples2.GetCount(5));
 
   // Extreme case.
-  EXPECT_DEATH_IF_SUPPORTED(samples2.Accumulate(0, 100), "");
-  EXPECT_DEATH_IF_SUPPORTED(samples2.Accumulate(10, 100), "");
+  EXPECT_DCHECK_DEATH(samples2.Accumulate(0, 100));
+  EXPECT_DCHECK_DEATH(samples2.Accumulate(10, 100));
 }
 
 TEST_F(SampleVectorTest, AddSubtractBucketNotMatchDeath) {
@@ -192,20 +192,20 @@ TEST_F(SampleVectorTest, AddSubtractBucketNotMatchDeath) {
 
   // Extra bucket in the beginning.
   samples2.Accumulate(0, 100);
-  EXPECT_DEATH_IF_SUPPORTED(samples1.Add(samples2), "");
-  EXPECT_DEATH_IF_SUPPORTED(samples1.Subtract(samples2), "");
+  EXPECT_DCHECK_DEATH(samples1.Add(samples2));
+  EXPECT_DCHECK_DEATH(samples1.Subtract(samples2));
 
   // Extra bucket in the end.
   samples2.Accumulate(0, -100);
   samples2.Accumulate(6, 100);
-  EXPECT_DEATH_IF_SUPPORTED(samples1.Add(samples2), "");
-  EXPECT_DEATH_IF_SUPPORTED(samples1.Subtract(samples2), "");
+  EXPECT_DCHECK_DEATH(samples1.Add(samples2));
+  EXPECT_DCHECK_DEATH(samples1.Subtract(samples2));
 
   // Bucket not match: [3, 5) VS [3, 6)
   samples2.Accumulate(6, -100);
   samples2.Accumulate(3, 100);
-  EXPECT_DEATH_IF_SUPPORTED(samples1.Add(samples2), "");
-  EXPECT_DEATH_IF_SUPPORTED(samples1.Subtract(samples2), "");
+  EXPECT_DCHECK_DEATH(samples1.Add(samples2));
+  EXPECT_DCHECK_DEATH(samples1.Subtract(samples2));
 }
 
 TEST_F(SampleVectorTest, Iterate) {