Factor cpu profile tree into separate element and expose allocation tracing UI

runtime/vm/profiler_service.cc

Index: runtime/vm/profiler_service.cc
diff --git a/runtime/vm/profiler_service.cc b/runtime/vm/profiler_service.cc
index fac0bf4b25fa05d07b0226a5dfd8206f8a58f31a..29620231c7b0e3ec9e608bfe916bd40bea97501b 100644
--- a/runtime/vm/profiler_service.cc
+++ b/runtime/vm/profiler_service.cc
@@ -1238,7 +1238,7 @@ class ProfileBuilder : public ValueObject {
             current,
             i,
             (j == 0),
-            sample->first_frame_executing(),
+            sample->first_frame_executing() || (sample->allocation_cid() > 0),

[rmacnak, 2015/07/14 17:20:29]

is_allocation_sample()

[Cutch, 2015/07/14 20:02:57]

Done.

             true);
       }
     }
@@ -1266,7 +1266,7 @@ class ProfileBuilder : public ValueObject {
             current,
             i,
             (j == 0),
-            sample->first_frame_executing(),
+            sample->first_frame_executing() || (sample->allocation_cid() > 0),

[rmacnak, 2015/07/14 17:20:29]

is_allocation_sample()

[Cutch, 2015/07/14 20:02:57]

Done.

             false);
       }