patch from chinmaygarde@ to make progress on mac, ios.

build/config/compiler/BUILD.gn

Index: build/config/compiler/BUILD.gn
diff --git a/build/config/compiler/BUILD.gn b/build/config/compiler/BUILD.gn
index af14840f414ee597b884d69ab350955d848a29cd..821abedf08c504626fa6dc18fcd600cdd959b5cc 100644
--- a/build/config/compiler/BUILD.gn
+++ b/build/config/compiler/BUILD.gn
@@ -269,7 +269,7 @@ config("compiler") {
     } else if (current_cpu == "arm") {

[sdefresne, 2015/07/25 19:15:29]

I think we should add support for "armv7" and "arm64" cpu here too. Being able
to build for armv7 is useful when we have to debug issues that only happens on
non-64-bit devices (i.e. anything older than an iPhone 5s).

I would even go one step further and recommend removing support of "arm" as a
cpu as this is too ambiguous. There are three different ARM architecture that
are supported on iOS "armv7", "armv7s" and "arm64". Since we make the
distinction between "x86" and "x64" on Intel architecture even though "x64" cpu
can run "x86" code (the same as "arm64" do support "armv7" code), I think we
should do the same distinction for ARM architecture.

For webrtc, we can probably change their script to set target_cpu="arm64"
instead of target_cpu="arm".

[Dirk Pranke, 2015/07/31 21:27:40]

This seems reasonable but well out of the scope of what I want to do in this
patch. I'll add a TODO.

I would like to try and find names that work for both ios and android.

       common_mac_flags += [
         "-arch",
-        "armv7",
+        "arm64",
       ]
     }