Build addr2line-pdb from tcmalloc for use in memory-infra symbolization

BUILD.gn

Index: BUILD.gn
diff --git a/BUILD.gn b/BUILD.gn
index 1c9bb954acc172fdc2c56d5fd2b2375273cbb6ae..f54da3d66f0314a6cdf1418b20f999b75c0e2322 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -754,6 +754,10 @@ group("gn_only") {
     }
   }
 
+  if (is_win) {
+    deps += [ "//third_party/tcmalloc:addr2line-pdb" ]

[scottmg, 2017/03/03 00:20:24]

There's no such thing as gyp any more so this should go up near line 660, I
think.

[awong, 2017/03/06 18:45:52]

I was told to move it down hear in an earlier review... since I'm a know-nothing
noogler at this point...who should I listen to? :)

[erikchen, 2017/03/06 19:31:17]

I'm the one who asked for this move. This group is called gn_only and the group
above is both_gn_and_gyp. 

+  }
+
   if (is_linux && !is_chromeos && !is_chromecast) {
     # TODO(GYP): Figure out if any of these should be in gn_all
     # and figure out how cross-platform they are