Modify base_unittests.exe to use tcmalloc

base/base.gyp

Index: base/base.gyp
diff --git a/base/base.gyp b/base/base.gyp
index 290961eb44a0531a5b5f4fad705eb7fbb3c6ade7..1e0222e0efab589631d6df267a1861357fa32819 100644
--- a/base/base.gyp
+++ b/base/base.gyp
@@ -743,9 +743,9 @@
             'message_pump_glib_unittest.cc',
           ]
         }],
-        # This is needed to trigger the dll copy step on windows.
-        # TODO(mark): This should not be necessary.
         ['OS == "win"', {
+          # This is needed to trigger the dll copy step on windows.
+          # TODO(mark): This should not be necessary.
           'dependencies': [
             '../third_party/icu/icu.gyp:icudata',
           ],
@@ -759,6 +759,18 @@
           'msvs_disabled_warnings': [
             4267,
           ],
+          # This is needed so base_unittests uses the allocator shim, as
+          # SecurityTest.MemoryAllocationRestriction* tests are dependent
+          # on tcmalloc.
+          # TODO(wfh): crbug.com/246278 Move tcmalloc specific tests into
+          # their own test suite.
+          'conditions': [
+            ['win_use_allocator_shim==1', {
+              'dependencies': [
+                'allocator/allocator.gyp:allocator',
+              ],
+            }],
+          ],
         }, {  # OS != "win"
           'dependencies': [
             '../third_party/libevent/libevent.gyp:libevent'