Move ssl_browsertest.cc to weblayer/browser so that weblayer/test is only test support code.

This follows the convention for other directories, which is that tests live alongside the code they test.

Also update the readme.

Change-Id: I2f3ecd135825572f78930e09a99419ab5b8c257c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1900566
Auto-Submit: John Abd-El-Malek <jam@chromium.org>
Commit-Queue: Colin Blundell <blundell@chromium.org>
Reviewed-by: Colin Blundell <blundell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#712991}

weblayer/README.md

@@ -23,12 +23,20 @@ Bug tracker: [Internals>WebLayer](https://bugs.chromium.org/p/chromium/issues/li
 
 `shell` sample app
 
+'test' test harnesses and test-only helper code
+
+'tools' helper scripts
+
+'app' internal code which runs at the beginning of each process
+
 `browser` internal code which runs in the browser process
 
 `common` internal code which runs in the browser and child processes
 
 `renderer` internal code which runs in the renderer process
 
+`utility` internal code which runs in the utility process
+
 ## Setting Up Your Build Environment
 
 If you haven't done this already, you first need to set up an Android build. If

weblayer/test/BUILD.gn

@@ -87,11 +87,11 @@ test("weblayer_browsertests") {
   ]
 
   sources = [
+    "../browser/ssl_browsertest.cc",
     "../browser/webui/webui_browsertest.cc",
     "browsertests_main.cc",
     "interstitial_utils.cc",
     "interstitial_utils.h",
-    "ssl_browsertest.cc",
     "test_launcher_delegate_impl.cc",
     "test_launcher_delegate_impl.h",
     "weblayer_browser_test.cc",