ARM64 capable toolchain hash

This updates Chrome to build with a toolchain based on VS 2017 15.9.3
and the Windows 10.0.17763.132 SDK, with the ARM64 components included to
support building for ARM64 for Win32. This adds about 400 MB to the package
size, a bit less than a 50% increase.

Packaging was done on a Windows Server 2016 VM, cleanly created for this
purpose.

The package was created by downloading VS 2017 Update 9.3, from
https://www.visualstudio.com/vs/, and then running the installer like this:

$ PATH_TO_INSTALLER.EXE ^
    --add Microsoft.VisualStudio.Workload.NativeDesktop ^
    --add Microsoft.VisualStudio.Component.VC.ATLMFC ^
    --add Microsoft.VisualStudio.Component.VC.Tools.ARM64 ^
    --add Microsoft.VisualStudio.Component.VC.MFC.ARM64 ^
    --includeRecommended --passive

Then Add or Remove Programs was used to modify the SDK to add the
Debuggers package.

Then the packaging script was run like this:

  python depot_tools\win_toolchain\package_from_installed.py 2017 -w 10.0.17763.0

This was tested on two VMs to ensure that the results are consistent.

This should not significantly affect the x86 and x64 builds, although
there may have been some STL and CRT changes that could cause changes.

Bug: 893460
Change-Id: I33dd5b915ffaf17f306d804f561d26bf82060b03
Reviewed-on: https://chromium-review.googlesource.com/c/1342814
Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Reviewed-by: Nico Weber <thakis@chromium.org>
Commit-Queue: Bruce Dawson <brucedawson@chromium.org>
Cr-Commit-Position: refs/heads/master@{#616123}

build/vs_toolchain.py

@@ -404,9 +404,8 @@ def _GetDesiredVsToolchainHashes():
   to build with."""
   env_version = GetVisualStudioVersion()
   if env_version == '2017':
-    # VS 2017 Update 7.1 (15.7.1) with 10.0.17134.12 SDK, rebuilt with
-    # dbghelp.dll fix.
-    toolchain_hash = '3bc0ec615cf20ee342f3bc29bc991b5ad66d8d2c'
+    # VS 2017 Update 9 (15.9.3) with 10.0.17763.132 SDK, with ARM64 libraries.
+    toolchain_hash = 'e04af53255fe13c130e9cfde7d9ac861b9fb674a'
     # Third parties that do not have access to the canonical toolchain can map
     # canonical toolchain version to their own toolchain versions.
     toolchain_hash_mapping_key = 'GYP_MSVS_HASH_%s' % toolchain_hash