Enable tracing in SkyShell

sky/shell/org/domokit/sky/shell/TracingController.java

Index: sky/shell/org/domokit/sky/shell/TracingController.java
diff --git a/sky/shell/org/domokit/sky/shell/TracingController.java b/sky/shell/org/domokit/sky/shell/TracingController.java
new file mode 100644
index 0000000000000000000000000000000000000000..716e0c007d833cdd46b65c79537436af446a9d53
--- /dev/null
+++ b/sky/shell/org/domokit/sky/shell/TracingController.java
@@ -0,0 +1,75 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.domokit.sky.shell;
+
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+import android.content.IntentFilter;
+import android.os.Environment;
+import android.util.Log;
+
+import java.io.File;
+import java.text.SimpleDateFormat;
+import java.util.Date;
+import java.util.Locale;
+import java.util.TimeZone;
+
+import org.chromium.base.JNINamespace;
+
+/**
+ * A controller for the tracing system.
+ */
+@JNINamespace("sky::shell")
+class TracingController {
+    private static final String TAG = "TracingController";
+    private static final String TRACING_START = ".TRACING_START";
+    private static final String TRACING_STOP = ".TRACING_STOP";
+
+    private final Context mContext;
+    private final TracingBroadcastReceiver mBroadcastReceiver;
+    private final TracingIntentFilter mIntentFilter;
+
+    public TracingController(Context context) {
+        mContext = context;
+        mBroadcastReceiver = new TracingBroadcastReceiver();
+        mIntentFilter = new TracingIntentFilter(context);
+
+        mContext.registerReceiver(mBroadcastReceiver, mIntentFilter);
+    }
+
+    private String generateTracingFilePath() {
+        SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd-HHmmss", Locale.US);
+        formatter.setTimeZone(TimeZone.getTimeZone("UTC"));
+        File dir = mContext.getCacheDir();
+        String date = formatter.format(new Date());
+        File file = new File(dir, "sky-trace-" + date + ".json");
+        return file.getPath();
+    }
+
+    class TracingIntentFilter extends IntentFilter {
+        TracingIntentFilter(Context context) {
+            Log.e(TAG, context.getPackageName() + TRACING_START);
+            addAction(context.getPackageName() + TRACING_START);
+            addAction(context.getPackageName() + TRACING_STOP);
+        }
+    }
+
+    class TracingBroadcastReceiver extends BroadcastReceiver {
+        @Override
+        public void onReceive(Context context, Intent intent) {
+            if (intent.getAction().endsWith(TRACING_START)) {
+                nativeStartTracing();
+            } else if (intent.getAction().endsWith(TRACING_STOP)) {
+                nativeStopTracing(generateTracingFilePath());
+            } else {
+                Log.e(TAG, "Unexpected intent: " + intent);
+            }
+        }
+    }
+
+    private static native void nativeStartTracing();
+    private static native void nativeStopTracing(String path);
+}