mac: Add a profiler for startup time.

tools/metrics/histograms/histograms.xml

Index: tools/metrics/histograms/histograms.xml
diff --git a/tools/metrics/histograms/histograms.xml b/tools/metrics/histograms/histograms.xml
index feed2d6493d55bdb71b68bf29d5195c3587f53be..a162dc1d1153939cf839fe4d73b9182d1335f511 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -18921,6 +18921,63 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   <summary>Events seen by the OSX NSException swizzle.</summary>
 </histogram>
 
+<histogram name="OSX.Startup.AwakeFromNib" units="milliseconds">
+  <owner>erikchen@chromium.org</owner>
+  <summary>
+    The amount of time that elapses between the launch of Chrome and the

[Ilya Sherman, 2014/07/15 18:14:24]

Optional nit: I'd change the tense from present ("elapses") to past ("elapsed")

[erikchen, 2014/07/15 21:39:43]

Done.

+    invocation of -[AppControllerMac awakeFromNib].
+  </summary>
+</histogram>
+
+<histogram name="OSX.Startup.DidFinishLaunching" units="milliseconds">
+  <owner>erikchen@chromium.org</owner>
+  <summary>
+    The amount of time that elapses between the launch of Chrome and the
+    invocation of -[AppControllerMac didFinishLaunching:]. This is the amount of
+    time it takes for the dock icon to stop bouncing.
+  </summary>
+</histogram>
+
+<histogram name="OSX.Startup.PostMainMessageLoopStart" units="milliseconds">
+  <owner>erikchen@chromium.org</owner>
+  <summary>
+    The amount of time that elapses between the launch of Chrome and the
+    invocation of ChromeBrowserMainPartsMac::PostMainMessageLoopStart.
+  </summary>
+</histogram>
+
+<histogram name="OSX.Startup.PostProfileInit" units="milliseconds">
+  <owner>erikchen@chromium.org</owner>
+  <summary>
+    The amount of time that elapses between the launch of Chrome and the
+    invocation of ChromeBrowserMainPartsMac::PostProfileInit.
+  </summary>
+</histogram>
+
+<histogram name="OSX.Startup.PreMainMessageLoopStart" units="milliseconds">
+  <owner>erikchen@chromium.org</owner>
+  <summary>
+    The amount of time that elapses between the launch of Chrome and the
+    invocation of ChromeBrowserMainPartsMac::PreMainMessageLoopStart.
+  </summary>
+</histogram>
+
+<histogram name="OSX.Startup.PreProfileInit" units="milliseconds">
+  <owner>erikchen@chromium.org</owner>
+  <summary>
+    The amount of time that elapses between the launch of Chrome and the
+    invocation of ChromeBrowserMainPartsMac::PreProfileInit.
+  </summary>
+</histogram>
+
+<histogram name="OSX.Startup.WillFinishLaunching" units="milliseconds">
+  <owner>erikchen@chromium.org</owner>
+  <summary>
+    The amount of time that elapses between the launch of Chrome and the
+    invocation of -[AppControllerMac willFinishLaunching:].
+  </summary>
+</histogram>
+
 <histogram name="OutdatedUpgradeBubble.NumLaterPerEnableAU">
   <owner>mad@chromium.org</owner>
   <summary>