Return a NULL histogram pointer on construction error

chrome/renderer/pepper/pepper_uma_host.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/renderer/pepper/pepper_uma_host.h"
 
 #include "base/metrics/histogram.h"
 #include "base/sha1.h"
 #include "base/strings/string_number_conversions.h"
 #include "chrome/common/chrome_switches.h"
@@ skipping 94 matching lines @@
   }
   RETURN_IF_BAD_ARGS(min, max, bucket_count);
 
   base::HistogramBase* counter =
       base::Histogram::FactoryTimeGet(
           name,
           base::TimeDelta::FromMilliseconds(min),
           base::TimeDelta::FromMilliseconds(max),
           bucket_count,
           base::HistogramBase::kUmaTargetedHistogramFlag);
-  counter->AddTime(base::TimeDelta::FromMilliseconds(sample));
+  // The histogram can be NULL if it is constructed with bad arguments.  Ignore
+  // that data for this API.  An error message will be logged.
+  if (counter)
+    counter->AddTime(base::TimeDelta::FromMilliseconds(sample));
   return PP_OK;
 }
 
 int32_t PepperUMAHost::OnHistogramCustomCounts(
     ppapi::host::HostMessageContext* context,
     const std::string& name,
     int32_t sample,
     int32_t min,
     int32_t max,
     uint32_t bucket_count) {
   if (!IsHistogramAllowed(name)) {
     return PP_ERROR_NOACCESS;
   }
   RETURN_IF_BAD_ARGS(min, max, bucket_count);
 
   base::HistogramBase* counter =
       base::Histogram::FactoryGet(
           name,
           min,
           max,
           bucket_count,
           base::HistogramBase::kUmaTargetedHistogramFlag);
-  counter->Add(sample);
+  // The histogram can be NULL if it is constructed with bad arguments.  Ignore
+  // that data for this API.  An error message will be logged.
+  if (counter)
+    counter->Add(sample);
   return PP_OK;
 }
 
 int32_t PepperUMAHost::OnHistogramEnumeration(
     ppapi::host::HostMessageContext* context,
     const std::string& name,
     int32_t sample,
     int32_t boundary_value) {
   if (!IsHistogramAllowed(name)) {
     return PP_ERROR_NOACCESS;
   }
   RETURN_IF_BAD_ARGS(0, boundary_value, boundary_value + 1);
 
   base::HistogramBase* counter =
       base::LinearHistogram::FactoryGet(
           name,
           1,
           boundary_value,
           boundary_value + 1,
           base::HistogramBase::kUmaTargetedHistogramFlag);
-  counter->Add(sample);
+  // The histogram can be NULL if it is constructed with bad arguments.  Ignore
+  // that data for this API.  An error message will be logged.
+  if (counter)
+    counter->Add(sample);
   return PP_OK;
 }