Fix unused variable warning in compiler/debug.cpp.
Fix unused variable warning in compiler/debug.cpp.

BUG=angle:534

Change-Id: I893e552628c7deba4bc67baae6e5e28b6161c5d4
Reviewed-on: https://chromium-review.googlesource.com/178438
Reviewed-by: Geoff Lang <b6fc25fe0362055230985c05cbfa8adb741ccc0f@chromium.org>
Commit-Queue: Geoff Lang <b6fc25fe0362055230985c05cbfa8adb741ccc0f@chromium.org>
Tested-by: Geoff Lang <b6fc25fe0362055230985c05cbfa8adb741ccc0f@chromium.org>

crezefire/angle,mikolalysenko/angle,bsergean/angle,xin3liang/platform_external_chromium_org_third_party_angle,crezefire/angle,android-ia/platform_external_chromium_org_third_party_angle,android-ia/platform_external_chromium_org_third_party_angle,csa7mdm/angle,mybios/angle,mrobinson/rust-angle,vvuk/angle,MSOpenTech/angle,geekboxzone/lollipop_external_chromium_org_third_party_angle,xin3liang/platform_external_chromium_org_third_party_angle,geekboxzone/lollipop_external_chromium_org_third_party_angle,bsergean/angle,android-ia/platform_external_chromium_org_third_party_angle,jgcaaprom/android_external_chromium_org_third_party_angle,ecoal95/angle,MSOpenTech/angle,mikolalysenko/angle,ppy/angle,ecoal95/angle,mrobinson/rust-angle,MIPS/external-chromium_org-third_party-angle,vvuk/angle,ppy/angle,jgcaaprom/android_external_chromium_org_third_party_angle,geekboxzone/lollipop_external_chromium_org_third_party_angle,larsbergstrom/angle,domokit/waterfall,ghostoy/angle,mlfarrell/angle,xin3liang/platform_external_chromium_org_third_party_angle,domokit/waterfall,mrobinson/rust-angle,crezefire/angle,vvuk/angle,MSOpenTech/angle,jgcaaprom/android_external_chromium_org_third_party_angle,larsbergstrom/angle,mikolalysenko/angle,mikolalysenko/angle,mrobinson/rust-angle,ppy/angle,mybios/angle,ppy/angle,MSOpenTech/angle,MIPS/external-chromium_org-third_party-angle,bsergean/angle,nandhanurrevanth/angle,mrobinson/rust-angle,ecoal95/angle,MIPS/external-chromium_org-third_party-angle,android-ia/platform_external_chromium_org_third_party_angle,crezefire/angle,mybios/angle,larsbergstrom/angle,nandhanurrevanth/angle,csa7mdm/angle,mlfarrell/angle,mlfarrell/angle,nandhanurrevanth/angle,geekboxzone/lollipop_external_chromium_org_third_party_angle,ghostoy/angle,csa7mdm/angle,xin3liang/platform_external_chromium_org_third_party_angle,jgcaaprom/android_external_chromium_org_third_party_angle,ecoal95/angle,ghostoy/angle,larsbergstrom/angle,mlfarrell/angle,MIPS/external-chromium_org-third_party-angle,mybios/angle,csa7mdm/angle,nandhanurrevanth/angle,ecoal95/angle,ghostoy/angle,bsergean/angle,vvuk/angle