Revert "Add Dawn, SPIRV-Cross and GLFW to //third_party"

This reverts commit 382f385.

Reason for revert: crbug.com/895592

Original change's description:
> Add Dawn, SPIRV-Cross and GLFW to //third_party
> 
> Dawn is a library implementing WebGPU in native. It uses SPIRV-Cross to
> translate shaders from SPIRV to other shading languages, and requires
> glfw for testing.
> 
> Adds the Zlib license to the list of allowed license for Android.
> 
> This also adds back shaderc that was very recently removed. So hopefully
> a new third_party review isn't required.
> 
> BUG=chromium:870747
> 
> Change-Id: I506156072f34e70e12797f922a979aa8c743bd6e
> Reviewed-on: https://chromium-review.googlesource.com/c/1244817
> Reviewed-by: Will Harris <wfh@chromium.org>
> Reviewed-by: Jochen Eisinger <jochen@chromium.org>
> Reviewed-by: dsinclair <dsinclair@chromium.org>
> Reviewed-by: Kai Ninomiya <kainino@chromium.org>
> Commit-Queue: Corentin Wallez <cwallez@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#599740}

TBR=dsinclair@chromium.org,cwallez@chromium.org,wfh@chromium.org,kainino@chromium.org,jochen@chromium.org,dominic@google.com

Change-Id: I861d000856773e66a6a2c060ae737599b3be3e4d
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: chromium:870747
Reviewed-on: https://chromium-review.googlesource.com/c/1281879
Reviewed-by: John Budorick <jbudorick@chromium.org>
Commit-Queue: John Budorick <jbudorick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#599793}

BUILD.gn

@@ -144,8 +144,6 @@ group("gn_all") {
       "//third_party/SPIRV-Tools/src:SPIRV-Tools",
       "//third_party/SPIRV-Tools/src/test/fuzzers",
       "//third_party/cacheinvalidation:cacheinvalidation_unittests",
-      "//third_party/dawn:dawn_end2end_tests",
-      "//third_party/dawn:dawn_unittests",
       "//third_party/pdfium/samples:pdfium_test",
       "//third_party/webrtc/rtc_tools:frame_analyzer",
       "//tools/perf/clear_system_cache",

DEPS

@@ -92,12 +92,11 @@ vars = {
 
   'android_git': 'https://android.googlesource.com',
   'aomedia_git': 'https://aomedia.googlesource.com',
-  'boringssl_git': 'https://boringssl.googlesource.com',
   'chromium_git': 'https://chromium.googlesource.com',
-  'dawn_git': 'https://dawn.googlesource.com',
+  'swiftshader_git': 'https://swiftshader.googlesource.com',
   'pdfium_git': 'https://pdfium.googlesource.com',
+  'boringssl_git': 'https://boringssl.googlesource.com',
   'skia_git': 'https://skia.googlesource.com',
-  'swiftshader_git': 'https://swiftshader.googlesource.com',
   'webrtc_git': 'https://webrtc.googlesource.com',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling sfntly
@@ -219,18 +218,6 @@ vars = {
   # the commit queue can handle CLs rolling feed
   # and whatever else without interference from each other.
   'spv_headers_revision': '801cca8104245c07e8cc53292da87ee1b76946fe',
-  # Three lines of non-changing comments so that
-  # the commit queue can handle CLs rolling feed
-  # and whatever else without interference from each other.
-  'spirv_cross_revision': '69b034f26e28a76a6f4e5d9521123072b24d7ea2',
-  # Three lines of non-changing comments so that
-  # the commit queue can handle CLs rolling feed
-  # and whatever else without interference from each other.
-  'shaderc_revision': '196d38f64e4d919ddb26557f176ca134e2d88ddc',
-  # Three lines of non-changing comments so that
-  # the commit queue can handle CLs rolling feed
-  # and whatever else without interference from each other.
-  'dawn_revision': '16092faa163b20f6b85ff407b1ec1d61cb9d7f2a',
 }
 
 # Only these hosts are allowed for dependencies in this DEPS file.
@@ -242,7 +229,6 @@ allowed_hosts = [
   'chrome-infra-packages.appspot.com',
   'chrome-internal.googlesource.com',
   'chromium.googlesource.com',
-  'dawn.googlesource.com',
   'pdfium.googlesource.com',
   'skia.googlesource.com',
   'swiftshader.googlesource.com',
@@ -404,14 +390,6 @@ deps = {
       'dep_type': 'cipd',
   },
 
-  # SPIRV-Cross is in third_party/spirv-cross/spirv-cross instead of
-  # third_party/spirv-cross/src  because its header files are at the root of
-  # the repository and dependencies include them like so:
-  #   #include "spirv-cross/spirv_glsl.hpp"
-  'src/third_party/spirv-cross/spirv-cross':
-    Var('chromium_git') + '/external/github.com/KhronosGroup/SPIRV-Cross.git@' +
-        Var('spirv_cross_revision'),
-
   'src/third_party/spirv-headers/src':
     Var('chromium_git') + '/external/github.com/KhronosGroup/SPIRV-Headers.git@' +
         Var('spv_headers_revision'),
@@ -420,10 +398,6 @@ deps = {
     Var('chromium_git') + '/external/github.com/KhronosGroup/SPIRV-Tools.git@' +
         Var('spv_tools_revision'),
 
-  'src/third_party/shaderc/src':
-    Var('chromium_git') + '/external/github.com/google/shaderc.git@' +
-        Var('shaderc_revision'),
-
   'src/third_party/accessibility_test_framework': {
       'packages': [
           {
@@ -550,12 +524,6 @@ deps = {
   'src/third_party/angle':
     Var('chromium_git') + '/angle/angle.git' + '@' +  Var('angle_revision'),
 
-  'src/third_party/dawn':
-    Var('dawn_git') + '/dawn.git' + '@' +  Var('dawn_revision'),
-
-  'src/third_party/glfw/src':
-    Var('chromium_git') + '/external/github.com/glfw/glfw.git@' +  '096efdf798896cff80a0b2db08d7398b703406fe',
-
   'src/third_party/apache-portable-runtime/src': {
       'url': Var('chromium_git') + '/external/apache-portable-runtime.git' + '@' + 'c3f11fcd86b42922834cae91103cf068246c6bb6',
       'condition': 'checkout_android',
@@ -724,7 +692,7 @@ deps = {
   },
 
   'src/third_party/glslang/src':
-    Var('chromium_git') + '/external/github.com/KhronosGroup/glslang.git' + '@' + 'ca042a0ffbb6fe09a47c1c867d911b3a69d2102e',
+    Var('chromium_git') + '/external/github.com/google/glslang.git' + '@' + 'ec1476b7060306fd9109faf7a4c70a20ea3b538c',
 
   'src/third_party/google_toolbox_for_mac/src': {
       'url': Var('chromium_git') + '/external/github.com/google/google-toolbox-for-mac.git' + '@' + Var('google_toolbox_for_mac_revision'),

third_party/.gitignore

@@ -58,7 +58,6 @@
 /cros_system_api
 /custom_tabs_client/src
 /cygwin
-/dawn
 /depot_tools
 /devtools-node-modules
 /directxsdk
@@ -77,7 +76,6 @@
 /gestures/gestures
 /gles1_conform
 /gles2_conform
-/glfw/src
 /glslang/src
 /glslang-angle/src
 /gn/
@@ -199,7 +197,6 @@
 /smhasher/src
 /snappy/src
 /speex
-/spirv-cross/spirv-cross
 /spirv-headers/src
 /SPIRV-Tools/src
 /spirv-tools-angle/src

third_party/PRESUBMIT.py

@@ -18,7 +18,6 @@
   'SGI Free Software License B',
   'University of Illinois\/NCSA Open Source',
   'X11',
-  'Zlib',
 ]
 
 def LicenseIsCompatibleWithAndroid(input_api, license):