Add .gitignore files in build/ and third_party/

.gitignore

Index: .gitignore
diff --git a/.gitignore b/.gitignore
index b31263039d5cd18a49443ae44e0df9a0a8a1ac5a..cf2aea2eb8c953d2e69e7ea5e42c0a583cdb0b8d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -62,23 +62,7 @@ vs-chromium-project.txt
 /ash/ash_unittests_run.xml
 /base/base_unittests_run.xml
 /breakpad/src/
-/build/android/bin
-/build/Debug
-/build/Debug_x64
-/build/goma
-/build/gomacc.lock
-/build/ipch/
-/build/Release
-/build/Release_x64
-/build/win_toolchain.json
-/build/util/LASTCHANGE*
-/build/util/support
-/build/x64/
-/build/linux/bin/eu-strip
-/build/linux/debian_*-sysroot/
-/build/linux/ubuntu_*-sysroot/
-/build/ios_files
-/build/mac_files
+# See build/.gitignore for entries covering src/build.
 /buildtools
 # The Chrome OS build creates a /c symlink due to http://crbug.com/54866.
 /c
@@ -289,202 +273,7 @@ vs-chromium-project.txt
 /tools/luci-go/linux64/isolate
 /tools/luci-go/mac64/isolate
 /tools/luci-go/win64/isolate.exe
-/third_party/__START__
-/third_party/accessibility-developer-tools/
-/third_party/accessibility_test_framework/lib/*.jar
-/third_party/adobe/flash/binaries
-/third_party/adobe/flash/symbols
-/third_party/amd/
-/third_party/android_protobuf/src
-/third_party/android_support_test_runner/lib/*.aar
-/third_party/android_support_test_runner/lib/*.jar
-/third_party/android_tools/
-/third_party/android_tools_internal/
-/third_party/android_webview_glue/src
-/third_party/angle
-/third_party/angle_dx11
-/third_party/apache-portable-runtime/src
-/third_party/apache_velocity/lib/*.jar
-/third_party/apache-win32/bin/*.exe
-/third_party/apache-win32/bin/*.dll
-/third_party/apache-win32/bin/iconv/*.so
-/third_party/apache-win32/modules/*.so
-/third_party/apache-win32/modules/*.dll
-/third_party/asan
-/third_party/bidichecker
-/third_party/bison
-/third_party/boringssl/src
-/third_party/bouncycastle/lib/*.jar
-/third_party/byte_buddy/lib/*.jar
-/third_party/cacheinvalidation/cacheinvalidation_unittests_run.xml
-/third_party/cardboard-java/src
-/third_party/catapult
-/third_party/ced/src
-/third_party/chromeos_login_manager
-/third_party/chromeos_text_input
-/third_party/chromite
-/third_party/cld_2/src
-/third_party/cld_3/src
-/third_party/colorama/src
-/third_party/cros
-/third_party/cros_system_api
-/third_party/custom_tabs_client/src
-/third_party/cygwin
-/third_party/deqp/src
-/third_party/directxsdk
-/third_party/dom_distiller_js/dist
-/third_party/drmemory/drmemory-windows-sfx.exe
-/third_party/drmemory/unpacked
-/third_party/elfutils/src
-/third_party/errorprone/lib
-/third_party/espresso/lib/*.jar
-/third_party/eyesfree/src
-/third_party/ffmpeg
-/third_party/findbugs
-/third_party/flac
-/third_party/flatbuffers/src
-/third_party/fontconfig/src
-/third_party/freetype-android/src
-/third_party/freetype2/src
-/third_party/gestures/gestures
-/third_party/gles2_conform
-/third_party/glslang/src
-/third_party/glslang-angle/src
-/third_party/gnu_binutils/
-/third_party/google_appengine_cloudstorage
-/third_party/google_toolbox_for_mac/src
-/third_party/googlemac
-/third_party/gvr-android-sdk/common_library.aar
-/third_party/gvr-android-sdk/libgvr_shim_static_arm.a
-/third_party/gvr-android-sdk/libgvr_shim_static_arm64.a
-/third_party/gvr-android-sdk/src
-/third_party/gperf
-/third_party/guava/lib/*.jar
-/third_party/hamcrest/lib/*.jar
-/third_party/hunspell_dictionaries
-/third_party/icu
-/third_party/icu4j/lib/*.jar
-/third_party/intellij/lib/*.jar
-/third_party/inspector_protocol
-/third_party/javax_inject/lib/*.jar
-/third_party/jsoncpp/source
-/third_party/jsr-305/src
-/third_party/junit/src
-/third_party/khronos_glcts
-/third_party/leakcanary/src
-/third_party/leveldatabase/src
-/third_party/leveldb
-/third_party/libc++-static/libc++.a
-/third_party/libaddressinput/src
-/third_party/libdrm/src
-/third_party/libevdev/src
-/third_party/libexif/sources
-/third_party/libFuzzer/src
-/third_party/libjingle/source
-/third_party/libjpeg_turbo
-/third_party/liblouis/src
-/third_party/libphonenumber/dist
-/third_party/libsrtp
-/third_party/libupnp
-/third_party/libvpx/source/libvpx
-/third_party/libwebm/source
-/third_party/libyuv
-/third_party/lighttpd
-/third_party/llvm
-/third_party/llvm-allocated-type
-/third_party/llvm-bootstrap
-/third_party/llvm-build
-/third_party/lss
-/third_party/mesa/src
-/third_party/mingw-w64
-/third_party/minigbm/src
-/third_party/mkl
-/third_party/mocha
-/third_party/mockito/src
-/third_party/nacl_sdk_binaries/
-/third_party/netty-tcnative/src
-/third_party/netty4/src
-/third_party/node/linux
-/third_party/node/mac
-/third_party/node/node_modules
-/third_party/node/*.tar.gz
-/third_party/node/win
-/third_party/nss
-/third_party/objenesis/lib/*.jar
-/third_party/omaha/src/omaha
-/third_party/openmax_dl/
-/third_party/openh264/src
-/third_party/ow2_asm/lib/*.jar
-/third_party/pdfsqueeze
-/third_party/pdfium
-/third_party/pefile
-/third_party/perl
-/third_party/ppapi
-/third_party/psyco_win32
-/third_party/pthreads-win32
-/third_party/py_trace_event/src
-/third_party/pyelftools
-/third_party/pyftpdlib/src
-/third_party/pylib
-/third_party/pymox/src
-/third_party/python_24
-/third_party/python_26
-/third_party/pywebsocket/src
-/third_party/pywebsocket/src
-/third_party/re2/src
-/third_party/requests/src
-/third_party/retrolambda/*.jar
-/third_party/robolectric/lib/*.jar
-/third_party/robolectric/robolectric
-/third_party/scan-build/src
-/third_party/scons-2.0.1
-/third_party/sfntly/src
-/third_party/shaderc/src
-/third_party/skia
-/third_party/smhasher/src
-/third_party/snappy/src
-/third_party/spirv-headers/src
-/third_party/SPIRV-Tools/src
-/third_party/spirv-tools-angle/src
-/third_party/sqlite4java/lib/**/*.dll
-/third_party/sqlite4java/lib/**/*.jar
-/third_party/sqlite4java/lib/**/*.jnilib
-/third_party/sqlite4java/lib/**/*.so
-/third_party/swiftshader/
-/third_party/syzygy
-/third_party/syzygy/binaries
-/third_party/tsan/
-/third_party/ub-uiautomator/lib
-/third_party/usb_ids
-/third_party/usrsctp/usrsctplib
-/third_party/v8-i18n
-/third_party/valgrind
-/third_party/vulkan-validation-layers/src
-/third_party/visualmetrics
-/third_party/wayland/src
-/third_party/wayland-protocols/src
-/third_party/wds/src
-/third_party/webdriver/pylib
-/third_party/webdriver/python/selenium
-/third_party/webgl
-/third_party/webgl/src
-/third_party/webpagereplay/
-/third_party/webrtc
-/third_party/widevine/cdm/chromeos
-/third_party/widevine/cdm/linux
-/third_party/widevine/cdm/mac
-/third_party/widevine/cdm/win
-/third_party/widevine/scripts
-/third_party/widevine/test/license_server
-/third_party/win_toolchain/.timestamps
-/third_party/win_toolchain/files
-/third_party/wix
-/third_party/xdg-utils
-/third_party/xulrunner-sdk
-/third_party/yasm/binaries
-/third_party/yasm/generate_files.xml
-/third_party/yasm/source/patched-yasm
-/third_party/yasm/yasm.xml
+# See third_party/.gitignore for entries covering src/third_party.
 /tools/.bisect-builds-cache.json
 /tools/distcc
 /tools/gn/bin/linux