Remove some unused dependencies (#125)

DEPS

@@ -24,7 +24,7 @@ deps = {
   "third_party/externals/d3d12allocator"         : "https://skia.googlesource.com/external/github.com/GPUOpen-LibrariesAndSDKs/D3D12MemoryAllocator.git@169895d529dfce00390a20e69c2f516066fe7a3b",
   # Dawn requires jinja2 and markupsafe for the code generator, tint for SPIRV compilation, and abseil for string formatting.
   # When the Dawn revision is updated these should be updated from the Dawn DEPS as well.
-  "third_party/externals/dawn"                   : "https://dawn.googlesource.com/dawn.git@0d5e76a2427f1c629a0d709ee0833da43bf79e84",
+  # "third_party/externals/dawn"                   : "https://dawn.googlesource.com/dawn.git@0d5e76a2427f1c629a0d709ee0833da43bf79e84",
   "third_party/externals/jinja2"                 : "https://chromium.googlesource.com/chromium/src/third_party/jinja2@ee69aa00ee8536f61db6a451f3858745cf587de6",
   "third_party/externals/markupsafe"             : "https://chromium.googlesource.com/chromium/src/third_party/markupsafe@0944e71f4b2cb9a871bcbe353f95e889b64a611a",
   "third_party/externals/abseil-cpp"             : "https://skia.googlesource.com/external/github.com/abseil/abseil-cpp.git@cb436cf0142b4cbe47aae94223443df7f82e2920",
@@ -50,7 +50,7 @@ deps = {
   # "third_party/externals/perfetto"               : "https://android.googlesource.com/platform/external/perfetto@93885509be1c9240bc55fa515ceb34811e54a394",
   "third_party/externals/piex"                   : "https://android.googlesource.com/platform/external/piex.git@bb217acdca1cc0c16b704669dd6f91a1b509c406",
   "third_party/externals/sfntly"                 : "https://chromium.googlesource.com/external/github.com/googlei18n/sfntly.git@b55ff303ea2f9e26702b514cf6a3196a2e3e2974",
-  "third_party/externals/swiftshader"            : "https://swiftshader.googlesource.com/SwiftShader@ae667fe96db9b7f76edea242015d61f293c7210e",
+  # "third_party/externals/swiftshader"            : "https://swiftshader.googlesource.com/SwiftShader@ae667fe96db9b7f76edea242015d61f293c7210e",
   "third_party/externals/vulkanmemoryallocator"  : "https://chromium.googlesource.com/external/github.com/GPUOpen-LibrariesAndSDKs/VulkanMemoryAllocator@7de5cc00de50e71a3aab22dea52fbb7ff4efceb6",
   # vulkan-deps is a meta-repo containing several interdependent Khronos Vulkan repositories.
   # When the vulkan-deps revision is updated, those repos (spirv-*, vulkan-*) should be updated as well.