Setting is_component_build to false by default

webrtc/webrtc.gni

 # Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.
 #
 # Use of this source code is governed by a BSD-style license
 # that can be found in the LICENSE file in the root of the source
 # tree. An additional intellectual property rights grant can be found
 # in the file PATENTS.  All contributing project authors may
 # be found in the AUTHORS file in the root of the source tree.
 
 import("//build/config/arm.gni")
 import("//build/config/features.gni")
 import("//build/config/mips.gni")
 import("//build/config/sanitizers/sanitizers.gni")
 import("//build/config/ui.gni")
 import("//build_overrides/build.gni")
 import("//testing/test.gni")
+
+if (is_component_build) {
+  print("The Gn argument `is_component_build` is currently " +

[kjellander_webrtc, 2017/03/03 04:19:02]

How about replacing line 17-29 with just:
assert(!is_component_build, 
   """Please avoid using `is_component_build=true`

The GN argument `is_component_build` is currently ignored for WebRTC builds.
Component builds are supported by Chromium and the argument
`is_component_build` makes it possible to create shared libraries instead of
static libraries. If an app depends on WebRTC it makes sense to just depend on
the WebRTC static library, so there is no difference between
`is_component_build=true` and `is_component_build=false`

More info about component builds at: 
https://chromium.googlesource.com/chromium/src/+/master/docs/component_build.md
""")

[mbonadei, 2017/03/03 18:03:59]

Yeah, this would be cleaner than the current solution but it seems that newlines
are not supported in a string constant:
ERROR at //webrtc/webrtc.gni:18:10: Newline in string constant.
       """Please avoid using `is_component_build=true`.
         ^---------------------------------------------

And adding '\n' does not create a newline.

[kjellander_webrtc, 2017/03/03 19:10:03]

I see, then this is fine.

+        "ignored for WebRTC builds.")
+  print("Component builds are supported by Chromium and the argument " +
+        "`is_component_build` makes it possible to create shared libraries " +
+        "instead of static libraries.")
+  print("If an app depends on WebRTC it makes sense to just depend on the " +
+        "WebRTC static library, so there is no difference between " +
+        "`is_component_build=true` and `is_component_build=false`.")
+  print(
+      "More info about component builds at: " + "https://chromium.googlesource.com/chromium/src/+/master/docs/component_build.md")
+  assert(!is_component_build, "Please avoid using `is_component_build=true`.")

[kjellander_webrtc, 2017/03/03 19:10:03]

I suggest changing to "Please avoid using `Component builds are not supported in
WebRTC."

+}
+
 if (is_ios) {
   import("//build/config/ios/rules.gni")
 }
 
 declare_args() {
   # Disable this to avoid building the Opus audio codec.
   rtc_include_opus = true
 
   # Enable this if the Opus version upon which WebRTC is built supports direct
   # encoding of 120 ms packets.
@@ skipping 324 matching lines @@
       configs += invoker.configs
       configs -= rtc_remove_configs
       configs -= invoker.suppressed_configs
       public_configs = [ rtc_common_inherited_config ]
       if (defined(invoker.public_configs)) {
         public_configs += invoker.public_configs
       }
     }
   }
 }