Fix broken ETW dependency.
Fix broken ETW dependency.

We have 2 GYP files that create 'etw' targets, and these were conflicting at build time.

BUG=
R=sebmarchand@chromium.org

Review URL: https://codereview.appspot.com/60580044

git-svn-id: db59699583a60be9a535cd09cdc9132301867226@2027 15e8cca8-e42c-11de-a347-f34a4f72eb7d

wangming28/syzygy,supriyantomaftuh/syzygy,google/syzygy,sebmarchand/syzygy,sebmarchand/syzygy,ericmckean/syzygy,pombreda/syzygy,sebmarchand/syzygy,pombreda/syzygy,Eloston/syzygy,supriyantomaftuh/syzygy,sebmarchand/syzygy,pombreda/syzygy,wangming28/syzygy,Eloston/syzygy,wangming28/syzygy,pombreda/syzygy,google/syzygy,ericmckean/syzygy,ericmckean/syzygy,supriyantomaftuh/syzygy,pombreda/syzygy,ericmckean/syzygy,wangming28/syzygy,supriyantomaftuh/syzygy,ericmckean/syzygy,google/syzygy,sebmarchand/syzygy,google/syzygy