Make flow event traces disabled-by-default, and rename "ipc" and "task" categories to "toplevel"

base/debug/trace_event_memory_unittest.cc

 // Copyright 2013 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 "base/debug/trace_event_memory.h"
 
 #include <sstream>
 #include <string>
 
 #include "base/debug/trace_event_impl.h"
@@ skipping 146 matching lines @@
       "{"
       "\"current_allocs\": 68, "
       "\"current_bytes\": 4195, "
       "\"trace\": \"name \""
       "}";
   std::string output;
   EXPECT_TRUE(
       AppendHeapProfileLineAsTraceFormat(input.str().c_str(), &output));
   EXPECT_EQ(kExpectedOutput, output);
 
-  // Input with with the category "task".
+  // Input with with the category "toplevel".
   // TODO(jamescook): Eliminate this special case and move the logic to the
   // trace viewer code.
-  const char kTaskCategory[] = "task";
+  const char kTaskCategory[] = "toplevel";
   const char kTaskName[] = "TaskName";
   std::ostringstream input2;
   input2 << "   68:     4195 [  1087:    98009] @ " << &kTaskCategory << " "
         << &kTaskName;
   const std::string kExpectedOutput2 =
       ",\n"
       "{"
       "\"current_allocs\": 68, "
       "\"current_bytes\": 4195, "
       "\"trace\": \"TaskName->PostTask \""
@@ skipping 50 matching lines @@
   EXPECT_STREQ("null", StringFromHexAddress("0x0"));
   EXPECT_STREQ("error", StringFromHexAddress("not an address"));
   const char kHello[] = "hello";
   std::ostringstream hex_address;
   hex_address << &kHello;
   EXPECT_STREQ(kHello, StringFromHexAddress(hex_address.str()));
 }
 
 }  // namespace debug
 }  // namespace base