Add a Mojo EDK for Chrome that uses one OS pipe per message pipe.

chrome/browser/BUILD.gn

Index: chrome/browser/BUILD.gn
diff --git a/chrome/browser/BUILD.gn b/chrome/browser/BUILD.gn
index a8234becb6704dcdf3c2edefe63f746adafdf09f..de7720c849e5f95412052608609693bef0fa0f8d 100644
--- a/chrome/browser/BUILD.gn
+++ b/chrome/browser/BUILD.gn
@@ -314,7 +314,6 @@ source_set("browser") {
       "//third_party/leveldatabase",
       "//third_party/libaddressinput",
       "//third_party/libyuv",
-      "//third_party/mojo/src/mojo/edk/system",
       "//third_party/mojo/src/mojo/public/cpp/bindings",
       "//third_party/mojo/src/mojo/public/js",
       "//third_party/re2",
@@ -328,6 +327,12 @@ source_set("browser") {
       "//v8",
     ]
 
+    if (use_chrome_edk) {

[Ken Rockot(use gerrit already), 2015/09/23 22:32:17]

What if we added a few new group targets to //mojo/BUILD.gn to encompass these
conditional deps. I think it'd be nice to isolate usage of use_chrome_edk as
much as possible since we're almost certainly going to remove it some day.

Seems it's used most often for //mojo/edk/system, test runners, and
test_support. We could add a //mojo rule like

group("edk_system") {
  // logic to depend on either //mojo or //third_party based on flag
}

and then just depend on //mojo:edk_system here and everywhere else

Then someday when only the chrome EDK exists, cleanup is a simple find and
replace //mojo:edk_system -> //mojo/edk/system. This would also apply to rules
for run_all_unittests and test_support.


On a related note: several build files which reference use_chrome_edk now are
not importing features.gni and this makes GN sad. Of course that problem goes
away if we consolidate these conditional deps as suggested above.

+      deps += [ "//mojo/edk/system" ]
+    } else {
+      deps += [ "//third_party/mojo/src/mojo/edk/system" ]
+    }
+
     if (toolkit_views) {
       deps += [ "//ui/views" ]
     }