Added histograms on process singleton create when remote process exists and we cannot notify it

chrome/browser/process_singleton.h

 // 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.
 
 #ifndef CHROME_BROWSER_PROCESS_SINGLETON_H_
 #define CHROME_BROWSER_PROCESS_SINGLETON_H_
 
 #include "build/build_config.h"
 
 #if defined(OS_WIN)
@@ skipping 31 matching lines @@
 // each other.  It is named according to the user data directory, so
 // we can be sure that no more than one copy of the application can be
 // running at once with a given data directory.
 //
 // Implementation notes:
 // - the Windows implementation uses an invisible global message window;
 // - the Linux implementation uses a Unix domain socket in the user data dir.
 
 class ProcessSingleton : public base::NonThreadSafe {
  public:
+  // Used to send the reason of remote hang process termination as histogram.
+  enum RemoteHungProcessTerminateReason {
+    USER_ACCEPTED_TERMINATION,
+    NO_VISIBLE_WINDOW_FOUND,
+    NOTIFY_ATTEMPTS_EXCEEDED,
+    SOCKET_WRITE_FAILED,
+    SOCKET_READ_FAILED,
+    MAX_REMOTE_HUNG_PROCESS_TERMINATE_REASON

[gab, 2017/05/10 15:16:50]

This isn't a MAX, it's a COUNT or maybe END (since ends in C++'s are usually
past-the-end).

[Alexey Seren, 2017/05/11 13:42:05]

Acknowledged.

REMOTE_HUNG_PROCESS_TERMINATE_REASON_COUNT will be more appropriate.

+  };
+
+  // Used to send the result of interaction with remote process as histograms in
+  // case when remote process influences on start.
+  enum RemoteProcessInteractionResult {
+    TERMINATE_SUCCEEDED,
+    TERMINATE_FAILED,
+    TERMINATE_WAIT_TIMEOUT,
+    TERMINATE_NOT_ENOUGH_PERMISSIONS,
+    REMOTE_PROCESS_SHUTTING_DOWN,
+    PROFILE_UNLOCKED,
+    REMOTE_PROCESS_NOT_FOUND,
+    FAILED_TO_EXTRACT_PID,
+    INVALID_LOCK_FILE,
+    ORPHANED_LOCK_FILE,
+    SAME_BROWSER_INSTANCE,
+    REMOTE_PROCESS_NOTIFY_FAILED,
+    MAX_HUNG_REMOTE_PROCESS_ACTION
+  };
+
   // Logged as histograms, do not modify these values.
   enum NotifyResult {
     PROCESS_NONE = 0,
     PROCESS_NOTIFIED = 1,
     PROFILE_IN_USE = 2,
     LOCK_ERROR = 3,
     LAST_VALUE = LOCK_ERROR
   };
 
   static constexpr int kNumNotifyResults = LAST_VALUE + 1;
@@ skipping 116 matching lines @@
   // Helper class for linux specific messages.  LinuxWatcher is ref counted
   // because it posts messages between threads.
   class LinuxWatcher;
   scoped_refptr<LinuxWatcher> watcher_;
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(ProcessSingleton);
 };
 
 #endif  // CHROME_BROWSER_PROCESS_SINGLETON_H_