Add UMA histograms for policy loading.

chrome/browser/policy/config_dir_policy_loader.cc

Index: chrome/browser/policy/config_dir_policy_loader.cc
diff --git a/chrome/browser/policy/config_dir_policy_loader.cc b/chrome/browser/policy/config_dir_policy_loader.cc
index 5e6505833105530c1fc74b8835abebf31c341b6d..572a82d4085d6367829daefda32795e57c69570f 100644
--- a/chrome/browser/policy/config_dir_policy_loader.cc
+++ b/chrome/browser/policy/config_dir_policy_loader.cc
@@ -12,10 +12,12 @@
 #include "base/bind_helpers.h"
 #include "base/file_util.h"
 #include "base/json/json_file_value_serializer.h"
+#include "base/json/json_reader.h"
 #include "base/logging.h"
 #include "base/platform_file.h"
 #include "base/stl_util.h"
 #include "chrome/browser/policy/policy_bundle.h"
+#include "chrome/browser/policy/policy_load_status.h"
 
 namespace policy {
 
@@ -27,6 +29,31 @@ const base::FilePath::CharType kMandatoryConfigDir[] =
 const base::FilePath::CharType kRecommendedConfigDir[] =
     FILE_PATH_LITERAL("recommended");
 
+PolicyLoadStatus JsonErrorToPolicyLoadStatus(int status) {
+  switch (status) {
+    case JSONFileValueSerializer::JSON_ACCESS_DENIED:
+    case JSONFileValueSerializer::JSON_CANNOT_READ_FILE:
+    case JSONFileValueSerializer::JSON_FILE_LOCKED:
+      return POLICY_LOAD_STATUS_READ_ERROR;
+    case JSONFileValueSerializer::JSON_NO_SUCH_FILE:
+      return POLICY_LOAD_STATUS_MISSING;
+    case base::JSONReader::JSON_INVALID_ESCAPE:
+    case base::JSONReader::JSON_SYNTAX_ERROR:
+    case base::JSONReader::JSON_UNEXPECTED_TOKEN:
+    case base::JSONReader::JSON_TRAILING_COMMA:
+    case base::JSONReader::JSON_TOO_MUCH_NESTING:
+    case base::JSONReader::JSON_UNEXPECTED_DATA_AFTER_ROOT:
+    case base::JSONReader::JSON_UNSUPPORTED_ENCODING:
+    case base::JSONReader::JSON_UNQUOTED_DICTIONARY_KEY:
+      return POLICY_LOAD_STATUS_PARSE_ERROR;
+    case base::JSONReader::JSON_NO_ERROR:
+      NOTREACHED();
+      return POLICY_LOAD_STATUS_STARTED;
+  }
+  NOTREACHED() << "Invalid status " << status;
+  return POLICY_LOAD_STATUS_PARSE_ERROR;
+}
+
 }  // namespace
 
 ConfigDirPolicyLoader::ConfigDirPolicyLoader(const base::FilePath& config_dir,
@@ -97,6 +124,12 @@ void ConfigDirPolicyLoader::LoadFromPath(const base::FilePath& path,
        !config_file_path.empty(); config_file_path = file_enumerator.Next())
     files.insert(config_file_path);
 
+  PolicyLoadStatusSample status;
+  if (files.empty()) {
+    status.Add(POLICY_LOAD_STATUS_NO_POLICY);
+    return;
+  }
+
   // Start with an empty dictionary and merge the files' contents.
   // The files are processed in reverse order because |MergeFrom| gives priority
   // to existing keys, but the ConfigDirPolicyProvider gives priority to the
@@ -113,12 +146,14 @@ void ConfigDirPolicyLoader::LoadFromPath(const base::FilePath& path,
     if (!value.get()) {
       LOG(WARNING) << "Failed to read configuration file "
                    << config_file_iter->value() << ": " << error_msg;
+      status.Add(JsonErrorToPolicyLoadStatus(error_code));
       continue;
     }
     base::DictionaryValue* dictionary_value = NULL;
     if (!value->GetAsDictionary(&dictionary_value)) {
       LOG(WARNING) << "Expected JSON dictionary in configuration file "
                    << config_file_iter->value();
+      status.Add(POLICY_LOAD_STATUS_PARSE_ERROR);
       continue;
     }