Memory tracking is now handled by a service.

Multiple processes may be tracked and viewed simultaneously.

Also, some changes to the graph:
  * show uss and pss together
  * adjust opacity controls

Change-Id: I20eebaa8cc8faf78b46af2a35d71ee538207f02b
diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index baf6990..e1ad9f5 100644
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -125,6 +125,11 @@
             </intent-filter>
         </activity>
 
+        <service android:name="com.android.launcher3.MemoryTracker"
+            android:enabled="@bool/debug_memory_enabled"
+            >
+        </service>
+
         <!-- Intent received used to prepopulate the default workspace. -->
         <receiver
             android:name="com.android.launcher3.PreloadReceiver"