Make Tracing Service not use outgoing InterfaceProvider, update conventions

services/tracing/public/interfaces/tracing.mojom

Index: services/tracing/public/interfaces/tracing.mojom
diff --git a/services/tracing/public/interfaces/tracing.mojom b/services/tracing/public/interfaces/tracing.mojom
index b624f81e24f9da19b3c352d8b9c21b2e80bb8332..558f634507d04abe567529a9c46b36021c9e0e9f 100644
--- a/services/tracing/public/interfaces/tracing.mojom
+++ b/services/tracing/public/interfaces/tracing.mojom
@@ -2,25 +2,25 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-module tracing;
+module tracing.mojom;
 
-// To participate in the tracing ecosystem, implement the TraceProvider
-// interface and connect to the tracing app. Then, when the provider's Start()
-// function is called collect tracing data and pass it back via the provided
-// TraceRecorder interface up until Stop() is called.
+// To participate in the tracing ecosystem, implement the Provider interface
+// connect to the tracing service & create a Recorder. Then, when the provider's
+// Start() function is called collect tracing data and pass it back via the
+// provided Recorder interface up until Stop() is called.
 
-interface TraceProvider {
+interface Provider {
   // Categories can either be the empty string to mean the default set of
   // categories or a comma-delimited list of categories to trace.
-  StartTracing(string categories, TraceRecorder recorder);
+  StartTracing(string categories, Recorder recorder);
   StopTracing();
 };
 
-interface TraceRecorder {
+interface Recorder {
   Record(string json);
 };
 
-interface TraceCollector {
+interface Collector {
   // Request tracing data from all connected providers to stream to
   // |stream|.
   Start(handle<data_pipe_producer> stream, string categories);
@@ -60,3 +60,7 @@ interface StartupPerformanceDataCollector {
   // Get the currently available startup performance times.
   GetStartupPerformanceTimes() => (StartupPerformanceTimes times);
 };
+
+interface Factory {
+  CreateRecorder(Provider provider);
+};