Roll googletest to 1.7.0+.

third_party/.gitignore

 # This file is needed for projects that has this directory as a separate Git
 # mirror in DEPS. Without it, a lot is wiped and re-downloaded for each sync.
 /__START__
 /accessibility-developer-tools/
 /accessibility_test_framework/lib/accessibility-test-framework-2.1.jar
 /adobe/flash/binaries
 /adobe/flash/symbols
 /amd/
 /android_protobuf/src
 /android_support_test_runner/lib/*.aar
@@ skipping 48 matching lines @@
 /fontconfig/src
 /freetype/src
 /gestures/gestures
 /gles2_conform
 /glslang/src
 /glslang-angle/src
 /gnu_binutils/
 /google_appengine_cloudstorage
 /google_toolbox_for_mac/src
 /googlemac
+/googletest/src
 /gvr-android-sdk/common_library.aar
 /gvr-android-sdk/test-libraries/controller_test_api.aar
 /gvr-android-sdk/libgvr_shim_static_arm.a
 /gvr-android-sdk/libgvr_shim_static_arm64.a
 /gvr-android-sdk/src
 /gvr-android-sdk/test-apks/daydream_home/*.apk
 /gvr-android-sdk/test-apks/vr_services/*.apk
 /gperf
 /guava/lib/guava-20.0.jar
 /hamcrest/lib/*.jar
@@ skipping 121 matching lines @@
 /win_toolchain/files
 /wix
 /xdg-utils
 /xstream/lib/*.jar
 /xulrunner-sdk
 /yasm/binaries
 /yasm/generate_files.xml
 /yasm/source/patched-yasm
 /yasm/yasm.xml