Use use_allocator instead of android_use_tcmalloc to switch the allocator.

build/common.gypi

Index: build/common.gypi
diff --git a/build/common.gypi b/build/common.gypi
index 11ab19d78be400788248b43dfdcf1f8a0b68eb83..0915c27e60ad2fc077d02f821dfbdaf7cf825818 100644
--- a/build/common.gypi
+++ b/build/common.gypi
@@ -1177,11 +1177,12 @@
     'release_unwind_tables%': 1,
 
     # Enable TCMalloc.
-    # TODO(dmikurube): Change the default of use_allocator to "tcmalloc".
-    # TODO(dmikurube): Kill linux_use_tcmalloc. http://crbug.com/345554
+    # TODO(dmikurube): Change Linux default of use_allocator to "tcmalloc".
+    # TODO(dmikurube): Change Android default of use_allocator to "none".
+    # TODO(dmikurube): Kill {linux|android}_use_tcmalloc. http://crbug.com/345554
     # {linux|android}_use_tcmalloc are to be replaced with use_allocator.
     # They are now used only if use_allocator=="see_use_tcmalloc" (default).
-    # TODO(dmikurube): Assert when linux_use_tcmalloc is explicitly specified.
+    # TODO(dmikurube): Assert when {linux|android}_use_tcmalloc is explicitly specified.
     'linux_use_tcmalloc%': 1,
     'android_use_tcmalloc%': 0,
     'use_allocator%': 'see_use_tcmalloc',
@@ -3794,8 +3795,8 @@
               }],
             ],
           }],
-          # TODO(dmikurube): Kill linux_use_tcmalloc. http://crbug.com/345554
-          ['(use_allocator!="tcmalloc" and (use_allocator!="see_use_tcmalloc" or linux_use_tcmalloc==0)) and android_use_tcmalloc==0', {
+          # TODO(dmikurube): Kill {linux|android}_use_tcmalloc. http://crbug.com/345554
+          ['use_allocator!="tcmalloc" and (use_allocator!="see_use_tcmalloc" or ((OS=="linux" and linux_use_tcmalloc==0) or (OS=="android" and android_use_tcmalloc==0)))', {
             'defines': ['NO_TCMALLOC'],
           }],
           ['linux_use_gold_flags==1', {