Fixed a bug where the vertex data manager was not caching the current value attributes properly.
Fixed a bug where the vertex data manager was not caching the current
value attributes properly.

ANGLEBUG=489
Review URL: https://codereview.appspot.com/18400043

cvsuser-chromium/chromium-third-party_angle_dx11,android-ia/platform_external_chromium_org_third_party_angle,vvuk/angle-old,cantren/angleproject,MIPS/external-chromium_org-third_party-angle,jgcaaprom/android_external_chromium_org_third_party_angle,KalebDark/angleproject,geekboxzone/lollipop_external_chromium_org_third_party_angle,RepublicMaster/angleproject,RepublicMaster/angleproject,cantren/angleproject,cvsuser-chromium/chromium-third-party_angle_dx11,themusicgod1/angleproject,KalebDark/angleproject,geekboxzone/lollipop_external_chromium_org_third_party_angle,MIPS/external-chromium_org-third_party-angle,pombreda/angleproject,jgcaaprom/android_external_chromium_org_third_party_angle,geekboxzone/lollipop_external_chromium_org_third_party_angle,themusicgod1/angleproject,vvuk/angle-old,ehsan/angle,themusicgod1/angleproject,android-ia/platform_external_chromium_org_third_party_angle,xuxiandi/angleproject,geekboxzone/lollipop_external_chromium_org_third_party_angle,MIPS/external-chromium_org-third_party-angle,xin3liang/platform_external_chromium_org_third_party_angle_dx11,shairai/angleproject,cvsuser-chromium/chromium-third-party_angle_dx11,xin3liang/platform_external_chromium_org_third_party_angle_dx11,xin3liang/platform_external_chromium_org_third_party_angle,cvsuser-chromium/chromium-third-party_angle_dx11,RepublicMaster/angleproject,MIPS/external-chromium_org-third_party-angle,jgcaaprom/android_external_chromium_org_third_party_angle,ehsan/angle,xin3liang/platform_external_chromium_org_third_party_angle,KalebDark/angleproject,pombreda/angleproject,xuxiandi/angleproject,xin3liang/platform_external_chromium_org_third_party_angle_dx11,ehsan/angle,xin3liang/platform_external_chromium_org_third_party_angle_dx11,shairai/angleproject,android-ia/platform_external_chromium_org_third_party_angle,xuxiandi/angleproject,xin3liang/platform_external_chromium_org_third_party_angle,vvuk/angle-old,xin3liang/platform_external_chromium_org_third_party_angle,themusicgod1/angleproject,android-ia/platform_external_chromium_org_third_party_angle,ehsan/angle,KalebDark/angleproject,pombreda/angleproject,cantren/angleproject,xuxiandi/angleproject,cantren/angleproject,jgcaaprom/android_external_chromium_org_third_party_angle,vvuk/angle-old,shairai/angleproject,pombreda/angleproject,shairai/angleproject,RepublicMaster/angleproject