Fix componene debug build failure in chromium
Fix componene debug build failure in chromium

The error log is as follows:
../../third_party/skia/include/core/SkSpinlock.h:24: error: undefined reference to 'SkPODSpinlock::contendedAcquire()'
collect2: error: ld returned 1 exit status

[mtklein added below here]
Despite the presence in include/ and the added SK_API, this file is not part of Skia's public API... it's just used by files which are.
TBR=reed@google.com

Review URL: https://codereview.chromium.org/1229003004

vanish87/skia,pcwalton/skia,google/skia,Jichao/skia,ominux/skia,tmpvar/skia.cc,HalCanary/skia-hc,rubenvb/skia,qrealka/skia-hc,noselhq/skia,shahrzadmn/skia,tmpvar/skia.cc,aosp-mirror/platform_external_skia,vanish87/skia,ominux/skia,qrealka/skia-hc,shahrzadmn/skia,nvoron23/skia,HalCanary/skia-hc,HalCanary/skia-hc,ominux/skia,qrealka/skia-hc,rubenvb/skia,vanish87/skia,HalCanary/skia-hc,Hikari-no-Tenshi/android_external_skia,pcwalton/skia,google/skia,aosp-mirror/platform_external_skia,pcwalton/skia,nvoron23/skia,noselhq/skia,nvoron23/skia,noselhq/skia,Jichao/skia,Hikari-no-Tenshi/android_external_skia,vanish87/skia,todotodoo/skia,shahrzadmn/skia,HalCanary/skia-hc,nvoron23/skia,google/skia,tmpvar/skia.cc,tmpvar/skia.cc,shahrzadmn/skia,HalCanary/skia-hc,qrealka/skia-hc,rubenvb/skia,shahrzadmn/skia,google/skia,tmpvar/skia.cc,noselhq/skia,Jichao/skia,shahrzadmn/skia,aosp-mirror/platform_external_skia,pcwalton/skia,aosp-mirror/platform_external_skia,Hikari-no-Tenshi/android_external_skia,Jichao/skia,HalCanary/skia-hc,todotodoo/skia,Hikari-no-Tenshi/android_external_skia,aosp-mirror/platform_external_skia,qrealka/skia-hc,noselhq/skia,aosp-mirror/platform_external_skia,Hikari-no-Tenshi/android_external_skia,rubenvb/skia,google/skia,aosp-mirror/platform_external_skia,ominux/skia,aosp-mirror/platform_external_skia,ominux/skia,nvoron23/skia,Hikari-no-Tenshi/android_external_skia,vanish87/skia,vanish87/skia,Jichao/skia,tmpvar/skia.cc,todotodoo/skia,rubenvb/skia,tmpvar/skia.cc,shahrzadmn/skia,todotodoo/skia,shahrzadmn/skia,pcwalton/skia,pcwalton/skia,Hikari-no-Tenshi/android_external_skia,Jichao/skia,qrealka/skia-hc,Jichao/skia,pcwalton/skia,google/skia,rubenvb/skia,ominux/skia,vanish87/skia,todotodoo/skia,Hikari-no-Tenshi/android_external_skia,rubenvb/skia,qrealka/skia-hc,rubenvb/skia,HalCanary/skia-hc,vanish87/skia,todotodoo/skia,noselhq/skia,aosp-mirror/platform_external_skia,google/skia,pcwalton/skia,nvoron23/skia,shahrzadmn/skia,ominux/skia,Jichao/skia,nvoron23/skia,tmpvar/skia.cc,todotodoo/skia,Jichao/skia,noselhq/skia,todotodoo/skia,vanish87/skia,HalCanary/skia-hc,tmpvar/skia.cc,google/skia,noselhq/skia,aosp-mirror/platform_external_skia,rubenvb/skia,todotodoo/skia,google/skia,ominux/skia,pcwalton/skia,qrealka/skia-hc,rubenvb/skia,nvoron23/skia,HalCanary/skia-hc,google/skia,noselhq/skia,ominux/skia,nvoron23/skia