Add a --startup option to generate combined traces for startup.

tools/profile_chrome/chrome_controller.py

Index: tools/profile_chrome/chrome_controller.py
diff --git a/tools/profile_chrome/chrome_controller.py b/tools/profile_chrome/chrome_controller.py
index 9f522631b1e6e6591c49d595a8985f5657e78180..1176518c83f5e616333e8f305ee3f1adba319fbb 100644
--- a/tools/profile_chrome/chrome_controller.py
+++ b/tools/profile_chrome/chrome_controller.py
@@ -9,6 +9,8 @@ import time
 
 from profile_chrome import controllers
 
+from pylib import android_commands
+from pylib import flag_changer
 from pylib import pexpect
 from pylib.device import intent
 
@@ -17,7 +19,8 @@ _HEAP_PROFILE_MMAP_PROPERTY = 'heapprof.mmap'
 
 class ChromeTracingController(controllers.BaseController):
   def __init__(self, device, package_info,
-               categories, ring_buffer, trace_memory=False):
+               categories, ring_buffer, trace_memory=False,
+               startup=None):
     controllers.BaseController.__init__(self)
     self._device = device
     self._package_info = package_info
@@ -26,10 +29,15 @@ class ChromeTracingController(controllers.BaseController):
     self._trace_file = None
     self._trace_interval = None
     self._trace_memory = trace_memory
+    self._startup = startup
     self._is_tracing = False
     self._trace_start_re = \
        re.compile(r'Logging performance trace to file')
-    self._trace_finish_re = \
+    if self._startup:
+      self._trace_finish_re = re.compile(
+          r' Completed startup tracing to (.*)')
+    else:
+      self._trace_finish_re = \
        re.compile(r'Profiler finished[.] Results are in (.*)[.]')
     self._device.old_interface.StartMonitoringLogcat(clear=False)
 
@@ -59,7 +67,24 @@ class ChromeTracingController(controllers.BaseController):
 
     return list(record_categories), list(disabled_by_default_categories)
 
+  def _SetupStartupTracing(self):
+    changer = flag_changer.FlagChanger(
+        self._device, self._package_info.cmdline_file)
+    changer.AddFlags(['--trace-startup'])
+    self._device.old_interface.CloseApplication(self._package_info.package)
+    if self._startup == 'cold':
+      self._device.old_interface.EnableAdbRoot()
+      adb = android_commands.AndroidCommands()
+      adb.RunShellCommand('echo 1 > /proc/vm/drop_caches')

[pasko-google - do not use, 2015/01/27 15:20:52]

There is cache_control.DropRamCaches, which also drops inodes and directory
entries, maybe that is more representative of a cold start?

[Benoit L, 2015/01/27 16:31:33]

Done.

+    self._device.old_interface.StartActivity(
+        package=self._package_info.package,
+        activity=self._package_info.activity,
+        data='http://www.google.com/',
+        extras={'create_new_tab' : True})
+
   def StartTracing(self, interval):
+    if self._startup:
+      self._SetupStartupTracing()
     self._trace_interval = interval
     self._device.old_interface.SyncLogCat()
     start_extras = {'categories': ','.join(self._categories)}
@@ -80,13 +105,14 @@ class ChromeTracingController(controllers.BaseController):
     #
     # The first one is printed when tracing starts and the second one indicates
     # that the trace file is ready to be pulled.
-    try:
-      self._device.old_interface.WaitForLogMatch(
-          self._trace_start_re, None, timeout=5)
-      self._is_tracing = True
-    except pexpect.TIMEOUT:
-      raise RuntimeError('Trace start marker not found. Is the correct version '
-                         'of the browser running?')
+    if not self._startup:
+      try:
+        self._device.old_interface.WaitForLogMatch(
+            self._trace_start_re, None, timeout=5)
+      except pexpect.TIMEOUT:
+        raise RuntimeError('Trace start marker not found. Is the correct '
+                           'version of the browser running?')
+    self._is_tracing = True
 
   def StopTracing(self):
     if self._is_tracing:
@@ -101,7 +127,6 @@ class ChromeTracingController(controllers.BaseController):
   def PullTrace(self):
     # Wait a bit for the browser to finish writing the trace file.
     time.sleep(self._trace_interval / 4 + 1)
-
     trace_file = self._trace_file.replace('/storage/emulated/0/', '/sdcard/')
     host_file = os.path.join(os.path.curdir, os.path.basename(trace_file))
     self._device.PullFile(trace_file, host_file)