Use Mojo pipes to signal sync IPC events

ipc/BUILD.gn

Index: ipc/BUILD.gn
diff --git a/ipc/BUILD.gn b/ipc/BUILD.gn
index 4d515d7e7a229d1dba95d7b1036a05f3230eb850..2c0d797c2aeea2deda70dcd51be7f175ba9c50db 100644
--- a/ipc/BUILD.gn
+++ b/ipc/BUILD.gn
@@ -127,12 +127,16 @@ component("ipc") {
 
   public_deps = [
     ":param_traits",
+    "//mojo/public/cpp/bindings",
+    "//mojo/public/cpp/system",
   ]
+
   deps = [
     "//base",
 
     # TODO(viettrungluu): Needed for base/lazy_instance.h, which is suspect.
     "//base/third_party/dynamic_annotations",
+    "//mojo/public/c/system:for_component",
   ]
 
   if (is_win || is_mac) {
@@ -201,6 +205,7 @@ if (!is_ios) {
       "//base:i18n",
       "//base/test:test_support",
       "//crypto",
+      "//mojo/edk/system",
       "//testing/gtest",
     ]
 
@@ -226,6 +231,7 @@ if (!is_ios) {
       "//base:i18n",
       "//base/test:test_support",
       "//base/test:test_support_perf",
+      "//mojo/edk/system",
       "//testing/gtest",
     ]
   }
@@ -254,6 +260,7 @@ if (!is_ios) {
     deps = [
       "//base",
       "//base/test:test_support",
+      "//mojo/edk/system",
       "//testing/gtest",
     ]
   }