headless: Initial headless embedder API implementation

This patch introduces the initial headless embedder API implementation.
It allows the embedder to initialize a headless browsing environment and
to navigate to a URL.

We also add a headless shell application to demonstrate the use of the
embedder API.

Adapted from a patch by Alexander Timin <altimin@chromium.org>

BUG=546953

Review URL: https://codereview.chromium.org/1674263002

Cr-Commit-Position: refs/heads/master@{#377973}

1 files changed, 7 insertions, 0 deletions

diff --git a/BUILD.gn b/BUILD.gn
index 5956fa4..c013d45 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -728,6 +728,13 @@ group("gn_only") {
     ]
   }
 
+  if (is_linux && use_ozone) {
+    deps += [
+      "//headless",
+      "//headless:headless_tests",
+    ]
+  }
+
   if (!is_chromecast && (is_android || is_linux || is_chromeos)) {
     deps += [
       "//blimp",