Roll chromium_revision 6a04368..717238e (370362:370438) + tcmalloc

Change log: 6a04368..717238e
Full diff: 6a04368..717238e

Also add third_party/tcmalloc to the symlink list.
As per crrev.com/1611633003 host tools require tcmalloc.
No update to Clang.

BUG=chromium:580777

Review URL: https://codereview.webrtc.org/1629373002

Cr-Commit-Position: refs/heads/master@{#11369}

.gitignore

@@ -132,6 +132,7 @@
 /third_party/robolectric
 /third_party/sqlite
 /third_party/syzygy
+/third_party/tcmalloc
 /third_party/usrsctp
 /third_party/valgrind
 /third_party/WebKit

DEPS

@@ -6,7 +6,7 @@
 vars = {
   'extra_gyp_flag': '-Dextra_gyp_flag=0',
   'chromium_git': 'https://chromium.googlesource.com',
-  'chromium_revision': '4623ce800b2050be83f307f351fb5a8addf3e676',
+  'chromium_revision': '717238e9faac7bdd5a7a63fffdcee77e93d48e1f',
 }
 
 # NOTE: Prefer revision numbers to tags for svn deps. Use http rather than

setup_links.py

@@ -99,6 +99,7 @@ if 'android' in target_os:
     'third_party/modp_b64',
     'third_party/requests',
     'third_party/robolectric',
+    'third_party/tcmalloc',
     'tools/android',
     'tools/grit',
     'tools/telemetry',