mac: Expose keychain access frequency to Telemetry.

crypto/mock_apple_keychain.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 "base/logging.h"
 #include "base/perf_util.h"
 #include "base/time/time.h"
 #include "crypto/mock_apple_keychain.h"
 
 namespace crypto {
 
 OSStatus MockAppleKeychain::FindGenericPassword(
     CFTypeRef keychainOrArray,
     UInt32 serviceNameLength,
     const char* serviceName,
     UInt32 accountNameLength,
     const char* accountName,
     UInt32* passwordLength,
     void** passwordData,
     SecKeychainItemRef* itemRef) const {
   // Through manual testing, each call to SecKeychainFindGenericPassword takes
   // 4.6ms with a SSD, 3 GHz Intel Xeon. On a slower processor with a HDD, this
   // probably takes 4x as long.
   base::SpinCpuMicroseconds(18400);
+  base::EmitAccessKeychainHistogram();
 
   // When simulating |noErr|, return canned |passwordData| and
   // |passwordLength|.  Otherwise, just return given code.
   if (find_generic_result_ == noErr) {
     static const char kPassword[] = "my_password";
     DCHECK(passwordData);
     // The function to free this data is mocked so the cast is fine.
     *passwordData = const_cast<char*>(kPassword);
     DCHECK(passwordLength);
     *passwordLength = arraysize(kPassword);
@@ skipping 16 matching lines @@
     const char* serviceName,
     UInt32 accountNameLength,
     const char* accountName,
     UInt32 passwordLength,
     const void* passwordData,
     SecKeychainItemRef* itemRef) const {
   // Through manual testing, each call to SecKeychainAddGenericPassword takes
   // 6ms with a SSD, 3 GHz Intel Xeon. On a slower processor with a HDD, this
   // probably takes 4x as long.
   base::SpinCpuMicroseconds(24000);
+  base::EmitAccessKeychainHistogram();
 
   called_add_generic_ = true;
 
   DCHECK_GT(passwordLength, 0U);
   DCHECK(passwordData);
   add_generic_password_ =
       std::string(const_cast<char*>(static_cast<const char*>(passwordData)),
                   passwordLength);
   return noErr;
 }
 
 }  // namespace crypto