UMA metrics for cloud policies.

chrome/browser/policy/user_policy_token_cache.cc

 // Copyright (c) 2011 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/policy/user_policy_token_cache.h"
 
 #include "base/file_util.h"
+#include "base/metrics/histogram.h"
+#include "chrome/browser/policy/enterprise_metrics.h"
 #include "content/browser/browser_thread.h"
 
+namespace {
+
+// Other places can sample on the same UMA counter, so make sure they all do
+// it on the same thread (UI).
+void SampleUMAOnUIThread(policy::MetricToken sample) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  UMA_HISTOGRAM_ENUMERATION(policy::kMetricToken, sample,
+                            policy::kMetricTokenSize);
+}
+
+void SampleUMA(policy::MetricToken sample) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
+  BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
+                          NewRunnableFunction(&SampleUMAOnUIThread, sample));
+}
+
+}  // namespace
+
 namespace policy {
 
 namespace em = enterprise_management;
 
 UserPolicyTokenCache::Delegate::~Delegate() {}
 
 UserPolicyTokenCache::UserPolicyTokenCache(
     const base::WeakPtr<Delegate>& delegate,
     const FilePath& cache_file)
     : delegate_(delegate),
       cache_file_(cache_file) {}
 
 void UserPolicyTokenCache::Load() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  UMA_HISTOGRAM_ENUMERATION(kMetricToken, kMetricTokenLoadRequested,
+                            kMetricTokenSize);
   BrowserThread::PostTask(
       BrowserThread::FILE, FROM_HERE,
       NewRunnableMethod(this, &UserPolicyTokenCache::LoadOnFileThread));
 }
 
 void UserPolicyTokenCache::Store(const std::string& token,
                                  const std::string& device_id) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  UMA_HISTOGRAM_ENUMERATION(kMetricToken, kMetricTokenStoreRequested,
+                            kMetricTokenSize);
   BrowserThread::PostTask(
       BrowserThread::FILE, FROM_HERE,
       NewRunnableMethod(this,
                         &UserPolicyTokenCache::StoreOnFileThread,
                         token,
                         device_id));
 }
 
 UserPolicyTokenCache::~UserPolicyTokenCache() {
 }
 
 void UserPolicyTokenCache::LoadOnFileThread() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
   std::string device_token;
   std::string device_id;
 
   if (file_util::PathExists(cache_file_)) {
     std::string data;
     em::DeviceCredentials device_credentials;
     if (file_util::ReadFileToString(cache_file_, &data) &&
         device_credentials.ParseFromArray(data.c_str(), data.size())) {
       device_token = device_credentials.device_token();
       device_id = device_credentials.device_id();
+    } else {
+      SampleUMA(kMetricTokenLoadFailed);
     }
   }
 
   BrowserThread::PostTask(
       BrowserThread::UI, FROM_HERE,
       NewRunnableMethod(this,
                         &UserPolicyTokenCache::NotifyOnUIThread,
                         device_token,
                         device_id));
 }
 
 void UserPolicyTokenCache::NotifyOnUIThread(const std::string& token,
                                             const std::string& device_id) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   if (delegate_.get())
     delegate_->OnTokenCacheLoaded(token, device_id);
 }
 
 void UserPolicyTokenCache::StoreOnFileThread(const std::string& token,
                                              const std::string& device_id) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
   em::DeviceCredentials device_credentials;
   device_credentials.set_device_token(token);
   device_credentials.set_device_id(device_id);
   std::string data;
   bool success = device_credentials.SerializeToString(&data);
   if (!success) {
     LOG(WARNING) << "Failed serialize device token data, will not write "
                  << cache_file_.value();
+    SampleUMA(kMetricTokenStoreFailed);
     return;
   }
 
   if (!file_util::CreateDirectory(cache_file_.DirName())) {
     LOG(WARNING) << "Failed to create directory "
                  << cache_file_.DirName().value();
+    SampleUMA(kMetricTokenStoreFailed);
     return;
   }
 
-  file_util::WriteFile(cache_file_, data.c_str(), data.length());
+  int size = data.size();
+  if (file_util::WriteFile(cache_file_, data.c_str(), size) != size) {
+    LOG(WARNING) << "Failed to write " << cache_file_.value();
+    SampleUMA(kMetricTokenStoreFailed);
+  }
 }
 
 }  // namespace policy