Reland (2) of: Allow base to depend on allocator

Reason for reland:
Some targets (clearkeycdmadapter, osmesa) now fell in the state where
they depend indirectly on base (which causes the removal of the default
clib) but via a shared_library boundary (which does not propagate the
replacement allocator / shim layer code).
Fixing those targets by adding a direct base dependency.

This causes a breakage in the main waterfall:
https://build.chromium.org/p/chromium.win/builders/Win%20x64%20GN/builds/10231

Original CL description:
> A smaller, yet key, step to move
>
> From: a situation where mainly executables (but not really) depend on
> allocator, and base needs dependencies (to tcmalloc) to be injected
> from content (which violates the ODR in component buids).
>
> To: a situation where only base depends on allocator and the other
> targets get recursively the required linked flags.
>
> In essence this CL is a more gradual approach to the bigger
> unreviewable crrev.com/1528013002.
>
> How is the transition handled?
> ------------------------------
> After this CL, the situation will be as follows:
> From a build time perspective base will also depend on allocator.
> This will not change anything substantial in static builds and introduce
> yet another (temporary) ODR violation in Linux component builds.
> The big change introduced by this CL is the fact that all the executable
> targets that depend on base (virtualy all) will also get another
> indirect dependency to allocator.
>
> In other words, after this CL executable targets will depend on
> allocator for two reasons:
>  - Because they have an explicit dependency to it (the one I am going to
>    get rid of in the immediate future).
>  - Because this new transitive path I am introducing in base.
>
> Rationale of this approach
> --------------------------
> This allows to restrict the critical changes in a smaller CL easier to
> review, at the cost of the temporary double dependency on base.
> The good things are:
>  - If something will break, this CL will be very easy to revert.
>  - The next cleanups will be straightforward.
>  - We have now smoke tests (crrev.com/1577883002) that will help us
>    realize if something goes wrong.
>
> Next steps
> ----------
> In the next CLs I will:
>  - Remove the content -> base injection layer, and let base directly use
>    the tcmalloc functions it needs.
>  - Remove all the traces of USE_TCMALLOC outside of base.
>  - Start cleaning up the hundreds use_allocator conditionals in the gyp
>    files in a way which is easier to review and produce zero ninja diffs
>    (see crrev.com/1583973002 as an example)
>
> Ninja diffs caused by this change
> ---------------------------------
>  ### Win, static build, GN:   https://paste.ee/p/hvcRp
>  The missing targets (mostly tests) that previously were
>  not depending on allocator, now get that by virtue of the transitive
>  dependency.
>
>  ### Win, static build, GYP:  https://paste.ee/p/AGuKR
>  As above. Just GYP seems to emit the ninja files in a different,
>  inlined, format.
>
>  ### linux static build, GYP:  https://paste.ee/p/kmD7U
>  As above. Plus the new targets also get the -Wl,-u (keep symbol)
>  args as expected by allocator.gyp for the tcmalloc heap profiler.
>
>  ### linux shared build, GYP: https://paste.ee/p/FHHNR
>  Nothing relevant. Just I moved the dependency to allocator from
>  base_unittests to base, and that is the only thing that reflects in the
>  ninja files.
>
> BUG=564618

TBR=wfh@chromium.org,brettw@chromium.org,kbr@chromium.org
BUG=564618

Review URL: https://codereview.chromium.org/1616793003

Cr-Commit-Position: refs/heads/master@{#370694}

1 files changed, 4 insertions, 1 deletions

diff --git a/base/BUILD.gn b/base/BUILD.gn
index fe8ad86..3f8380c 100644
--- a/base/BUILD.gn
+++ b/base/BUILD.gn
@@ -953,6 +953,7 @@ component("base") {
   ]
 
   deps = [
+    "//base/allocator",
     "//base/third_party/dynamic_annotations",
     "//third_party/modp_b64",
   ]
@@ -1861,7 +1862,6 @@ test("base_unittests") {
     ":message_loop_tests",
     ":prefs",
     ":prefs_test_support",
-    "//base/allocator",
     "//base/test:run_all_unittests",
     "//base/test:test_support",
     "//base/third_party/dynamic_annotations",
@@ -1870,6 +1870,9 @@ test("base_unittests") {
     "//third_party/icu",
   ]
 
+  # Some unittests depend on the ALLOCATOR_SHIM macro.
+  configs += [ "//base/allocator:allocator_shim_define" ]
+
   data = [
     "test/data/",
   ]