Replace high-contrast-mode with dark-mode in Blink's web tests.

This is a follow-up to https://crrev.com/c/1500255.

Bug: 938511
Change-Id: If3a4f8a3488557808551da8180ff858522f23052
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1506872
Commit-Queue: Aran Gilman <gilmanmh@google.com>
Commit-Queue: Dominic Mazzoni <dmazzoni@chromium.org>
Auto-Submit: Aran Gilman <gilmanmh@google.com>
Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#638337}

third_party/blink/web_tests/VirtualTestSuites

@@ -432,18 +432,18 @@
     "args": ["--enable-print-browser"]
   },
   {
-    "prefix": "high-contrast-mode",
-    "base": "paint/high-contrast-mode/image-filter-all",
+    "prefix": "dark-mode",
+    "base": "paint/dark-mode/image-filter-all",
     "args": ["--blink-settings=highContrastMode=3,highContrastImagePolicy=0"]
   },
   {
-    "prefix": "high-contrast-mode",
-    "base": "paint/high-contrast-mode/image-filter-none",
+    "prefix": "dark-mode",
+    "base": "paint/dark-mode/image-filter-none",
     "args": ["--blink-settings=highContrastMode=3,highContrastImagePolicy=1"]
   },
   {
-    "prefix": "high-contrast-mode",
-    "base": "paint/high-contrast-mode/image-filter-smart",
+    "prefix": "dark-mode",
+    "base": "paint/dark-mode/image-filter-smart",
     "args": ["--blink-settings=highContrastMode=3,highContrastImagePolicy=2"]
   },
   {

third_party/blink/web_tests/virtual/high-contrast-mode/paint/high-contrast-mode/image-filter-all/README.txt → third_party/blink/web_tests/virtual/dark-mode/paint/dark-mode/image-filter-all/README.txt

-# This suite runs the tests in LayoutTests/paint/high-contrast-mode
+# This suite runs the tests in LayoutTests/paint/dark-mode
 # with --blink-settings="highContrastMode=3,highContrastImagePolicy=0"
 # See the virtual_test_suites() method in tools/blinkpy/web_tests/port/base.py.

third_party/blink/web_tests/virtual/high-contrast-mode/paint/high-contrast-mode/image-filter-none/README.txt → third_party/blink/web_tests/virtual/dark-mode/paint/dark-mode/image-filter-none/README.txt

-# This suite runs the tests in LayoutTests/paint/high-contrast-mode
+# This suite runs the tests in LayoutTests/paint/dark-mode
 # with --blink-settings="highContrastMode=3,highContrastImagePolicy=1"
 # See the virtual_test_suites() method in tools/blinkpy/web_tests/port/base.py.

third_party/blink/web_tests/virtual/high-contrast-mode/paint/high-contrast-mode/image-filter-smart/README.txt → third_party/blink/web_tests/virtual/dark-mode/paint/dark-mode/image-filter-smart/README.txt

-# This suite runs the tests in LayoutTests/paint/high-contrast-mode
+# This suite runs the tests in LayoutTests/paint/dark-mode
 # with --blink-settings="highContrastMode=3,highContrastImagePolicy=2"
 # See the virtual_test_suites() method in tools/blinkpy/web_tests/port/base.py.