[tracing] Add thread name to the pseudo stack of heap profiler

base/trace_event/heap_profiler_allocation_context_tracker_unittest.cc

 // 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.
 
 #include <stddef.h>
 
 #include <iterator>
 
 #include "base/memory/ref_counted.h"
 #include "base/trace_event/heap_profiler_allocation_context.h"
@@ skipping 211 matching lines @@
 
   {
     AllocationContext ctx =
         AllocationContextTracker::GetInstanceForCurrentThread()
             ->GetContextSnapshot();
     ASSERT_EQ(kCupcake, ctx.backtrace.frames[0]);
     ASSERT_EQ(kFroyo, ctx.backtrace.frames[11]);
   }
 }
 
+TEST_F(AllocationContextTrackerTest, SetCurrentThreadName) {
+  TRACE_EVENT0("Testing", kCupcake);
+
+  // Test if the thread name is inserted into backtrace.
+  const char kThread1[] = "thread1";
+  AllocationContextTracker::SetCurrentThreadName(kThread1);
+  AllocationContext ctx1 =
+      AllocationContextTracker::GetInstanceForCurrentThread()
+          ->GetContextSnapshot();
+  ASSERT_EQ(kThread1, ctx1.backtrace.frames[0]);
+  ASSERT_EQ(kCupcake, ctx1.backtrace.frames[1]);
+
+  // Test if the thread name is reset.
+  const char kThread2[] = "thread2";
+  AllocationContextTracker::SetCurrentThreadName(kThread2);
+  AllocationContext ctx2 =
+      AllocationContextTracker::GetInstanceForCurrentThread()
+          ->GetContextSnapshot();
+  ASSERT_EQ(kThread2, ctx2.backtrace.frames[0]);
+  ASSERT_EQ(kCupcake, ctx2.backtrace.frames[1]);
+}
+
 }  // namespace trace_event
 }  // namespace base