Chrome.BrowserCrashDumpAttempts needs to account for multiple dumps from the same browser process.

chrome/browser/metrics/metrics_service.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.
 
 //------------------------------------------------------------------------------
 // Description of the life cycle of a instance of MetricsService.
 //
 //  OVERVIEW
 //
 // A MetricsService instance is typically created at application startup.  It is
@@ skipping 779 matching lines @@
 
 void MetricsService::RecordBreakpadHasDebugger(bool has_debugger) {
   if (!has_debugger)
     IncrementPrefValue(prefs::kStabilityDebuggerNotPresent);
   else
     IncrementPrefValue(prefs::kStabilityDebuggerPresent);
 }
 
 #if defined(OS_WIN)
 void MetricsService::CountBrowserCrashDumpAttempts() {
-  base::string16 key_str(chrome::kBrowserCrashDumpAttemptsRegistryPath);
-  key_str += L"\\";
-  key_str += UTF8ToWide(chrome::kChromeVersion);
-
+  // Open the registry key for iteration.
   base::win::RegKey regkey;
   if (regkey.Open(HKEY_CURRENT_USER,
-                  key_str.c_str(),
+                  chrome::kBrowserCrashDumpAttemptsRegistryPath,
                   KEY_ALL_ACCESS) != ERROR_SUCCESS) {
     return;
   }
 
-  base::string16 temp_name;
-  DWORD temp_value = 0;
-  int crash_dump_attempts = 0;
+  // The values we're interested in counting are all prefixed with the version.
+  base::string16 chrome_version(base::ASCIIToUTF16(chrome::kChromeVersion));
+
+  // Track a list of values to delete. We don't modify the registry key while
+  // we're iterating over its values.
+  typedef std::vector<base::string16> StringVector;
+  StringVector to_delete;
+
+  // Iterate over the values in the key counting dumps with and without crashes.
+  // We directly walk the values instead of using RegistryValueIterator in order
+  // to read all of the values as DWORDS instead of strings.
+  base::string16 name;
+  DWORD value = 0;
+  int dumps_with_crash = 0;
+  int dumps_with_no_crash = 0;
   for (int i = regkey.GetValueCount() - 1; i >= 0; --i) {
-    if (regkey.GetValueNameAt(i, &temp_name) == ERROR_SUCCESS &&
-        regkey.ReadValueDW(temp_name.c_str(), &temp_value) == ERROR_SUCCESS) {
-      regkey.DeleteValue(temp_name.c_str());
-      if (temp_value != 0)
-        ++crash_dump_attempts;
+    if (regkey.GetValueNameAt(i, &name) == ERROR_SUCCESS &&
+        StartsWith(name, chrome_version, false) &&
+        regkey.ReadValueDW(name.c_str(), &value) == ERROR_SUCCESS) {
+      to_delete.push_back(name);
+      if (value == 0)
+        ++dumps_with_no_crash;
+      else
+        ++dumps_with_crash;
     }
   }
-  UMA_HISTOGRAM_COUNTS("Chrome.BrowserCrashDumpAttempts", crash_dump_attempts);
+
+  // Delete the registry keys we've just counted.
+  for (StringVector::iterator i = to_delete.begin(); i != to_delete.end(); ++i)
+    regkey.DeleteValue(i->c_str());
+
+  // Capture the histogram samples.
+  if (dumps_with_crash != 0)
+    UMA_HISTOGRAM_COUNTS("Chrome.BrowserDumpsWithCrash", dumps_with_crash);
+  if (dumps_with_no_crash != 0)
+    UMA_HISTOGRAM_COUNTS("Chrome.BrowserDumpsWithNoCrash", dumps_with_no_crash);
+  int total_dumps = dumps_with_crash + dumps_with_no_crash;
+  if (total_dumps != 0)
+    UMA_HISTOGRAM_COUNTS("Chrome.BrowserCrashDumpAttempts", total_dumps);
 }
 #endif  // defined(OS_WIN)
 
 //------------------------------------------------------------------------------
 // private methods
 //------------------------------------------------------------------------------
 
 
 //------------------------------------------------------------------------------
 // Initialization methods
@@ skipping 946 matching lines @@
   if (local_state) {
     const PrefService::Preference* uma_pref =
         local_state->FindPreference(prefs::kMetricsReportingEnabled);
     if (uma_pref) {
       bool success = uma_pref->GetValue()->GetAsBoolean(&result);
       DCHECK(success);
     }
   }
   return result;
 }