Example failing build:
https://ci.chromium.org/buildbot/chromium.clang/ToTWin%28dbg%29/383

Successful build on the chromium.win waterfall:
https://ci.chromium.org/buildbot/chromium.win/Win7%20Tests%20%28dbg%29%281%29/65557

There is some slight configuration difference between these bots that is causing some brower_tests to fail. These are the failing tests:

Mojo/ECKEncryptedMediaTest.MultipleCdmTypes/0
MediaRouterDialogControllerBrowserTest.RenderProcessHost
HostedAppTest.ShouldShowLocationBarForHostedApp/0
MetricsServiceBrowserTest.CheckCrashRenderers
NoStatePrefetchBrowserTest/NoStatePrefetchBrowserTest.RendererCrash/1
DevToolsReattachAfterCrashTest.TestReattachAfterCrashOnTimeline

The gn args are the same, except the main bot uses goma. Here's the main bot:

goma_dir = "C:\\b\\c\\goma_client"
is_component_build = true
is_debug = true
strip_absolute_paths_from_debug_symbols = true
symbol_level = 1
target_cpu = "x86"
use_goma = true

Here's ToTWin(dbg):

clang_use_chrome_plugins = false
is_clang = true
is_component_build = true
is_debug = true
llvm_force_head_revision = true
target_cpu = "x86"

Also, the corresponding x64 ToT bot is mostly green modulo flaky tests.