Update IdentifyChromeProcesses.py

IdentifyChromeProcesses.py can summarize Chrome's CPU usage and this
change improves how it does this. It includes CPU time from some extra
processes such as dwm.exe, audiodg.exe, System, MsMpEng.exe, and
software_reporter_tool.exe because the amount of CPU consumed by these
processes is sometimes affected by Chrome.

This change also adds summaries - for Chrome overall and per-process
type - of context switches, CPU usage, and number of processes. Again,
this helps to see trends that can otherwise be obscured by the number
of processes involved.

bin/IdentifyChromeProcesses.py

@@ -76,8 +76,14 @@ def main():
         # Chrome so I don't.
         if process_name == "chrome.exe":
           pid = int(pid)
-          cpu_usage_by_pid[pid] = float(cpu_usage.replace(",", ""));
+          cpu_usage_by_pid[pid] = float(cpu_usage.replace(",", ""))
           context_switches_by_pid[pid] = int(context_switches)
+        elif process_name in ['dwm.exe', 'audiodg.exe', 'System', 'MsMpEng.exe',
+                              'software_reporter_tool.exe']:
+          # Print information about other relevant processes:
+          print("%11s - %6d context switches, %8.2f ms CPU\r" % (process_name,
+                int(context_switches), float(cpu_usage.replace(",", ""))))
+      print("\r")
     else:
       print("Expected output file not found.")
       print("Expected to find: %s" % csv_filename)
@@ -145,6 +151,7 @@ def main():
         pidList.append(pid)
         pidsByType[type] = pidList
         pidsByParent[browserPid] = pidsByType
+
   # Scan a copy of the list of browser Pids looking for those with parents
   # in the list and no children. These represent child processes whose --type=
   # option was too far along in the command line for ETW's 512-character capture
@@ -198,7 +205,10 @@ def main():
           # deleted an entry, or else we might try to look it up.
           break
 
-  print("Chrome PIDs by process type:\r")
+  if len(pidsByParent.keys()) > 0:
+    print("Chrome PIDs by process type:\r")
+  else:
+    print("No Chrome processes found.\r")
   for browserPid in list(pidsByParent.keys()):
     # The crashpad fixes above should avoid this situation, but I'm leaving the
     # check to maintain robustness.
@@ -208,15 +218,29 @@ def main():
     if len(pidsByType) == 0:
       assert False
       continue
-    print("%s (%d)\r" % (exePath, browserPid))
     keys = list(pidsByType.keys())
     keys.sort()
+    total_processes = 0
+    total_context_switches = 0
+    total_cpu_usage = 0.0
+    for type in keys:
+      for pid in pidsByType[type]:
+        total_processes += 1
+        if show_cpu_usage and pid in cpu_usage_by_pid:
+          total_context_switches += context_switches_by_pid[pid]
+          total_cpu_usage += cpu_usage_by_pid[pid]
+    if show_cpu_usage:
+      print("%s (%d) - %d context switches, %8.2f ms CPU, %d processes\r" % (
+            exePath, browserPid, total_context_switches, total_cpu_usage,
+            total_processes))
+    else:
+      print("%s (%d) - %d processes\r" % (exePath, browserPid, total_processes))
     # Note the importance of printing the '\r' so that the
     # output will be compatible with Windows edit controls.
     for type in keys:
       print("    %-11s : " % type, end="")
       context_switches = 0
-      cpu_usage = 0
+      cpu_usage = 0.0
       if show_cpu_usage:
         for pid in pidsByType[type]:
           if pid in cpu_usage_by_pid:
@@ -227,7 +251,7 @@ def main():
       for pid in list_by_type:
         if show_cpu_usage:
           print("\r\n        ", end="")
-          if pid in cpu_usage_by_pid and len(list_by_type) > 1: # Skip per-process details if there's only one.:
+          if pid in cpu_usage_by_pid: # Skip per-process details if there's only one.:
             print("%5d - %6d context switches, %8.2f ms CPU" % (pid, context_switches_by_pid[pid], cpu_usage_by_pid[pid]), end="")
           else:
             print("%5d" % pid, end="")