Adding some tracing sections around launcher startup

Bug: 29007436
Change-Id: I53afd9130a2dc70a2223f1623e862faf44370f26
diff --git a/src/com/android/launcher3/LauncherModel.java b/src/com/android/launcher3/LauncherModel.java
index a5e703e..68a9c7e 100644
--- a/src/com/android/launcher3/LauncherModel.java
+++ b/src/com/android/launcher3/LauncherModel.java
@@ -37,6 +37,7 @@
 import android.os.Parcelable;
 import android.os.Process;
 import android.os.SystemClock;
+import android.os.Trace;
 import android.provider.BaseColumns;
 import android.text.TextUtils;
 import android.util.Log;
@@ -1542,6 +1543,9 @@
         }
 
         private void loadWorkspace() {
+            if (LauncherAppState.PROFILE_STARTUP) {
+                Trace.beginSection("Loading Workspace");
+            }
             final long t = DEBUG_LOADERS ? SystemClock.uptimeMillis() : 0;
 
             final Context context = mContext;
@@ -2157,6 +2161,9 @@
                     }
                 }
             }
+            if (LauncherAppState.PROFILE_STARTUP) {
+                Trace.endSection();
+            }
         }
 
         /**