Make MB aware of iOS bot configs and get iOS working.

ios/build/bots/tryserver.chromium.mac/ios_dbg_simulator_gn.json

Index: ios/build/bots/tryserver.chromium.mac/ios_dbg_simulator_gn.json
diff --git a/ios/build/bots/chromium.fyi/Chromium_iOS_Device_(ninja).json b/ios/build/bots/tryserver.chromium.mac/ios_dbg_simulator_gn.json
similarity index 50%
copy from ios/build/bots/chromium.fyi/Chromium_iOS_Device_(ninja).json
copy to ios/build/bots/tryserver.chromium.mac/ios_dbg_simulator_gn.json
index 54408813aab494e758ccd026b133cb8d3d0f71f7..c685fa74471d2348d56078a52d15bb3140e66cef 100644
--- a/ios/build/bots/chromium.fyi/Chromium_iOS_Device_(ninja).json
+++ b/ios/build/bots/tryserver.chromium.mac/ios_dbg_simulator_gn.json
@@ -1,18 +1,24 @@
 {
   "owners": [
+    "dpranke",
     "smut"
   ],
   "comments": [
-    "Builder for fat binaries using ninja."
+    "GN + Ninja simulator build."
   ],
   "xcode version": "7.0",
   "GYP_DEFINES": {
     "chromium_ios_signing": "0",
     "target_subarch": "both"
   },
+  "gn_args": [
+    "target_os=\"ios\"",
+    "use_ios_simulator=false"

[smut, 2015/11/18 22:00:29]

What is meant by use_ios_simulator=false? Are you skipping compilation of iossim
because you aren't running any tests below?

[Dirk Pranke, 2015/11/18 22:30:27]

I don't think iossim even builds yet in GN, period :).

Regardless, use_ios_simulator doesn't affect it. 

The flag is defined in //build/config/ios/ios_sdk.gni and only used there; 
it controls which SDK we build (iphonesimulator or iphoneos), and also
toggles a couple of defaults for code signing.

[smut, 2015/11/18 22:34:19]

Toggles SDK? Can you use what I set on line 21? That's supposed to say whether
it's iphoneos or iphonesimulator.

Also, if that's what it means, then shouldn't use_ios_simulator be true? This
should use iphonesimulator instead of iphoneos.

[Dirk Pranke, 2015/11/18 22:46:20]

Hmm. 

It looks like the way this is working is because GYP currently generates both
-iphoneos and -iphonesimulator configurations, and then you use 'sdk' to figure
out which directory to build (it generates 4 directories in total when you
multiple by Release/Debug) 

GN doesn't work that way; we only generate a single directory's worth of files.
So it needs to be told which config we want via gn_args.

We could modify MB to be aware of more stuff from the config file, but
that would make me increasingly unhappy. WDYT?
Yeah, actually I think this is just a typo on my part, so, good catch :).

[smut, 2015/11/18 23:02:40]

In that case can it be made clearer that this corresponds with the "sdk" entry?
e.g. sdk=\"iphonesimulator\" here and sdk=\"iphoneos\" in the device files.

use_ios_simulator doesn't seem to really indicate that it's about SDK.

[Dirk Pranke, 2015/11/19 01:05:25]

Let me fix all of the typos and try again. I'm getting lost at the moment
otherwise :).

+  ],
+  "mb_type": "gn",
   "compiler": "ninja",
-  "configuration": "Release",
-  "sdk": "iphoneos9.0",
+  "configuration": "Debug",
+  "sdk": "iphonesimulator9.0",
   "tests": [
   ]
 }