Histogram - add check for external LinearHistogram data with mismatching range.

chrome/browser/chromeos/external_metrics.cc

 // Copyright (c) 2012 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/browser/chromeos/external_metrics.h"
 
 #include <fcntl.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/file.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <unistd.h>
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/bind.h"
 #include "base/eintr_wrapper.h"
 #include "base/metrics/histogram.h"
+#include "base/metrics/statistics_recorder.h"
 #include "base/perftimer.h"
 #include "base/time.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/metrics/metrics_service.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/user_metrics.h"
 
 using content::BrowserThread;
 using content::UserMetricsAction;
 
 namespace chromeos {
 
 // The interval between external metrics collections in seconds
 static const int kExternalMetricsCollectionIntervalSeconds = 30;
 
 class SystemHistogram : public base::Histogram {
  public:
   static bool CheckValues(const std::string& name,
                           int minimum,
                           int maximum,
                           size_t bucket_count) {
     return base::Histogram::InspectConstructionArguments(
         name, &minimum, &maximum, &bucket_count);
   }
+  static bool CheckLinearValues(const std::string& name, int maximum) {
+    if (!CheckValues(name, 1, maximum, maximum + 1))
+      return false;
+    Histogram* histogram = base::StatisticsRecorder::FindHistogram(name);
+    if (!histogram)
+      return true;
+    return histogram->HasConstructionArguments(1, maximum, maximum + 1);
+  }
 };
 
 ExternalMetrics::ExternalMetrics()
     : test_recorder_(NULL) {
 }
 
 ExternalMetrics::~ExternalMetrics() {}
 
 void ExternalMetrics::Start() {
   // Register user actions external to the browser.
@@ skipping 61 matching lines @@
 
 void ExternalMetrics::RecordLinearHistogram(const char* histogram_data) {
   int sample, max;
   char name[128];   // length must be consistent with sscanf format below.
   int n = sscanf(histogram_data, "%127s %d %d", name, &sample, &max);
   if (n != 3) {
     LOG(ERROR) << "bad linear histogram request: " << histogram_data;
     return;
   }
 
-  if (!SystemHistogram::CheckValues(name, 1, max, max + 1)) {
+  if (!SystemHistogram::CheckLinearValues(name, max)) {
     LOG(ERROR) << "Invalid linear histogram " << name
                << ", max=" << max;
     return;
   }
   // Do not use the UMA_HISTOGRAM_... macros here.  They cache the Histogram
   // instance and thus only work if |name| is constant.
   base::Histogram* counter = base::LinearHistogram::FactoryGet(
       name, 1, max, max + 1, base::Histogram::kUmaTargetedHistogramFlag);
   counter->Add(sample);
 }
@@ skipping 119 matching lines @@
 void ExternalMetrics::ScheduleCollector() {
   bool result;
   result = BrowserThread::PostDelayedTask(
     BrowserThread::FILE, FROM_HERE,
     base::Bind(&chromeos::ExternalMetrics::CollectEventsAndReschedule, this),
     base::TimeDelta::FromSeconds(kExternalMetricsCollectionIntervalSeconds));
   DCHECK(result);
 }
 
 }  // namespace chromeos