Move tracing_impl code to mojo/common

sky/viewer/services/tracing_impl.cc

-// Copyright 2014 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.
-
-#include "sky/viewer/services/tracing_impl.h"
-
-#include "base/callback.h"
-#include "base/debug/trace_event.h"
-#include "base/files/file_util.h"
-
-namespace sky {
-namespace {
-
-static bool g_tracing = false;
-static int g_blocks = 0;
-static FILE* g_trace_file = NULL;
-
-void WriteTraceDataCollected(
-    const scoped_refptr<base::RefCountedString>& events_str,
-    bool has_more_events) {
-  if (g_blocks) {
-    fwrite(",", 1, 1, g_trace_file);
-  }
-  ++g_blocks;
-  fwrite(
-      events_str->data().c_str(), 1, events_str->data().length(), g_trace_file);
-  if (!has_more_events) {
-    fwrite("]}", 1, 2, g_trace_file);
-    base::CloseFile(g_trace_file);
-    g_trace_file = NULL;
-    g_blocks = 0;
-  }
-}
-
-void StopTracingAndFlushToDisk() {
-  base::debug::TraceLog::GetInstance()->SetDisabled();
-
-  g_trace_file = base::OpenFile(
-      base::FilePath(FILE_PATH_LITERAL("sky_viewer.trace")), "w+");
-  static const char start[] = "{\"traceEvents\":[";
-  fwrite(start, 1, strlen(start), g_trace_file);
-  base::debug::TraceLog::GetInstance()->Flush(
-      base::Bind(&WriteTraceDataCollected));
-}
-
-}
-
-TracingImpl::TracingImpl() {
-}
-
-TracingImpl::~TracingImpl() {
-}
-
-void TracingImpl::Start() {
-  if (g_tracing)
-    return;
-  g_tracing = true;
-  base::debug::TraceLog::GetInstance()->SetEnabled(
-      base::debug::CategoryFilter("*"),
-      base::debug::TraceLog::RECORDING_MODE,
-      base::debug::TraceOptions(base::debug::RECORD_UNTIL_FULL));
-}
-
-void TracingImpl::Stop() {
-  if (!g_tracing)
-    return;
-  g_tracing = false;
-  StopTracingAndFlushToDisk();
-}
-
-}  // namespace sky