Rolling 4 dependencies

Roll third_party/SPIRV-Tools/ 49ca250b4..2e1d208ed (3 commits)

https://chromium.googlesource.com/external/github.com/KhronosGroup/SPIRV-Tools/+log/49ca250b44c6..2e1d208ed9de

$ git log 49ca250b4..2e1d208ed --date=short --no-merges --format='%ad %ae %s'
2020-05-01 afdx spirv-fuzz: Do not allow adding stores to read-only pointers (#3316)
2020-04-30 paulthomson reduce: increase default step limit (#3327)
2020-04-30 afdx Generalize IsReadOnlyVariable() to apply to pointers (#3325)

Roll third_party/glslang/ 39281fb71..b5f003d7a (6 commits)

https://chromium.googlesource.com/external/github.com/KhronosGroup/glslang/+log/39281fb710c3..b5f003d7a3ec

$ git log 39281fb71..b5f003d7a --date=short --no-merges --format='%ad %ae %s'
2020-05-01 cepheus Fix #2191: Error check for indexing reference containing unsize array.
2020-05-01 cepheus GLSL: Separate out swizzle handling (potentially fixing bugs).
2020-04-21 pmistry Add support for es extension GL_EXT_blend_func_extended * Introduces builtin variables gl_SecondaryFragColorEXT and gl_SecondaryFragDataEXT * Introduces builtin constant gl_MaxDualSourceDrawBuffersEXT * enables support for layout qualifier "index" in es profile
2020-04-30 63069047+pmistryNV Add support for extension GL_EXT_shader_integer_mix (#2203)
2020-04-26 pmistry Add support for extension GL_EXT_shader_implicit_conversions Updated extension management in TIntermediate class.
2020-04-30 cepheus Fix #2201: Improve const and copy constructor for TVarLivePair.

Roll third_party/shaderc/ 41f271e61..15a66d72f (1 commit)

https://chromium.googlesource.com/external/github.com/google/shaderc/+log/41f271e6139c..15a66d72f33a

$ git log 41f271e61..15a66d72f --date=short --no-merges --format='%ad %ae %s'
2020-05-04 rharrison Rolling 5 dependencies and fixing build (#1057)

Roll third_party/spirv-cross/ 7e0295abf..92f7d36c7 (2 commits)

https://chromium.googlesource.com/external/github.com/KhronosGroup/SPIRV-Cross/+log/7e0295abf81c..92f7d36c72bc

$ git log 7e0295abf..92f7d36c7 --date=short --no-merges --format='%ad %ae %s'
2020-04-30 post MSL: Redirect member indices when buffer has been sorted by Offset.
2020-04-30 cwallez Fix -Wmicrosoft-enum-value

Created with:
  roll-dep third_party/SPIRV-Tools third_party/glslang third_party/shaderc third_party/spirv-cross third_party/spirv-headers

Change-Id: Ic556a6b7bdbbee47af3c2af5016de51d917766f8
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/21040
Reviewed-by: Ryan Harrison <rharrison@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Ryan Harrison <rharrison@chromium.org>
diff --git a/DEPS b/DEPS
index 825d18b..db7257b 100644
--- a/DEPS
+++ b/DEPS
@@ -61,13 +61,13 @@
 
   # SPIRV-Cross
   'third_party/spirv-cross': {
-    'url': '{chromium_git}/external/github.com/KhronosGroup/SPIRV-Cross@7e0295abf81cc939ecb2644c88592d77407d18d3',
+    'url': '{chromium_git}/external/github.com/KhronosGroup/SPIRV-Cross@92f7d36c72bc3cdbcc4aeff3534d096866013c0c',
     'condition': 'dawn_standalone',
   },
 
   # SPIRV compiler dependencies: SPIRV-Tools, SPIRV-headers, glslang and shaderc
   'third_party/SPIRV-Tools': {
-    'url': '{chromium_git}/external/github.com/KhronosGroup/SPIRV-Tools@49ca250b44c633ba7cb8897002e62781a451421c',
+    'url': '{chromium_git}/external/github.com/KhronosGroup/SPIRV-Tools@2e1d208ed9deab9048a00e60bb891d5e12a8332e',
     'condition': 'dawn_standalone',
   },
   'third_party/spirv-headers': {
@@ -75,11 +75,11 @@
     'condition': 'dawn_standalone',
   },
   'third_party/glslang': {
-    'url': '{chromium_git}/external/github.com/KhronosGroup/glslang@39281fb710c328998759a17132fd5a3dbe46dcf1',
+    'url': '{chromium_git}/external/github.com/KhronosGroup/glslang@b5f003d7a3ece37db45578a8a3140b370036fc64',
     'condition': 'dawn_standalone',
   },
   'third_party/shaderc': {
-    'url': '{chromium_git}/external/github.com/google/shaderc@41f271e6139ceb6a54457fb2da14571f66100a9a',
+    'url': '{chromium_git}/external/github.com/google/shaderc@15a66d72f33a099ec65e0fd37cf14548ed1d2bdb',
     'condition': 'dawn_standalone',
   },