Revert of Added a system caret used for accessibility on Windows.

ui/accessibility/BUILD.gn

Index: ui/accessibility/BUILD.gn
diff --git a/ui/accessibility/BUILD.gn b/ui/accessibility/BUILD.gn
index 324df01891fc16b01b2cb61c60d3ae5bde63c5a0..422dd09b1ca7b8c30d3eb42f4a71dc62ca07eebc 100644
--- a/ui/accessibility/BUILD.gn
+++ b/ui/accessibility/BUILD.gn
@@ -59,6 +59,8 @@
 
   if (has_native_accessibility) {
     sources += [
+      "platform/ax_fake_caret_win.cc",
+      "platform/ax_fake_caret_win.h",
       "platform/ax_platform_node.cc",
       "platform/ax_platform_node.h",
       "platform/ax_platform_node_base.cc",
@@ -68,8 +70,6 @@
       "platform/ax_platform_node_mac.mm",
       "platform/ax_platform_node_win.cc",
       "platform/ax_platform_node_win.h",
-      "platform/ax_system_caret_win.cc",
-      "platform/ax_system_caret_win.h",
     ]
   }
 
@@ -138,7 +138,6 @@
 }
 
 static_library("test_support") {
-  testonly = true
   sources = [
     "tree_generator.cc",
     "tree_generator.h",
@@ -157,7 +156,6 @@
 }
 
 test("accessibility_unittests") {
-  testonly = true
   sources = [
     "ax_generated_tree_unittest.cc",
     "ax_node_position_unittest.cc",
@@ -183,7 +181,6 @@
 
   if (is_win) {
     deps += [ "//third_party/iaccessible2" ]
-    libs = [ "oleacc.lib" ]
   }
 }