Support new systrace file structure after refactor

This is needed for
https://android-review.googlesource.com/#/c/154850/

Change-Id: Ibd5f33d0c038bfba37d81b23234945b9033c210a
Signed-off-by: Zhen Wang <zhenw@google.com>
diff --git a/build/sdk.atree b/build/sdk.atree
index 0d387ae..c0a163e 100644
--- a/build/sdk.atree
+++ b/build/sdk.atree
@@ -54,8 +54,12 @@
 development/sdk/generated-api-versions.xml    platform-tools/api/api-versions.xml
 
 # systrace
+external/chromium-trace/agents/__init__.py            platform-tools/systrace/agents/__init__.py
+external/chromium-trace/agents/atrace_agent.py        platform-tools/systrace/agents/atrace_agent.py
 external/chromium-trace/systrace.py                   platform-tools/systrace/systrace.py
 external/chromium-trace/systrace-legacy.py            platform-tools/systrace/systrace-legacy.py
+external/chromium-trace/systrace_agent.py             platform-tools/systrace/systrace_agent.py
+external/chromium-trace/util.py                       platform-tools/systrace/util.py
 external/chromium-trace/systrace_trace_viewer.html    platform-tools/systrace/systrace_trace_viewer.html
 external/chromium-trace/prefix.html                   platform-tools/systrace/prefix.html
 external/chromium-trace/suffix.html                   platform-tools/systrace/suffix.html