[Chromecast] Move content/web interfaces to "public" GN target

This facilitates mocking for unit tests without having to pull in all
of chromecast/browser.

Bug: None
Test: CQ
Change-Id: Ifeafdfeeffcdbf152a4d694f7cfc280cd5887e37
Reviewed-on: https://chromium-review.googlesource.com/1015960
Commit-Queue: Sean Topping <seantopping@chromium.org>
Reviewed-by: Stephen Lanham <slan@chromium.org>
Reviewed-by: Luke Halliwell <halliwell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#552849}

chromecast/browser/BUILD.gn

@@ -27,7 +27,6 @@ cast_source_set("browser") {
     "cast_browser_process.h",
     "cast_content_browser_client.cc",
     "cast_content_browser_client.h",
-    "cast_content_window.h",
     "cast_download_manager_delegate.cc",
     "cast_download_manager_delegate.h",
     "cast_http_user_agent_settings.cc",
@@ -49,7 +48,6 @@ cast_source_set("browser") {
     "cast_web_contents_manager.cc",
     "cast_web_contents_manager.h",
     "cast_web_view.cc",
-    "cast_web_view.h",
     "cast_web_view_default.cc",
     "cast_web_view_default.h",
     "cast_web_view_factory.cc",
@@ -89,6 +87,10 @@ cast_source_set("browser") {
     ]
   }
 
+  public_deps = [
+    ":public",
+  ]
+
   deps = [
     "//base",
     "//base:i18n",
@@ -266,6 +268,28 @@ cast_source_set("browser") {
   configs += [ "//media/audio:platform_config" ]
 }
 
+# Lightweight target for Cast interfaces that wrap //content/public/browser.
+# This target should only include interfaces which are required for unit tests.
+cast_source_set("public") {
+  sources = [
+    "cast_content_window.h",
+    "cast_web_view.h",
+  ]
+
+  # Need to expose this so that internal public_configs are propagated.
+  public_deps = [
+    "//content/public/browser",
+  ]
+
+  deps = [
+    "//base",
+    "//chromecast/graphics",
+    "//content",
+    "//ui/events",
+    "//url",
+  ]
+}
+
 # This target generates an "overlay" interface spec, allowing the Cast build to
 # declare specific behavior and requirements for the "content_browser" service.
 # This is accomplished by generating a JSON file, which is packed into

chromecast/browser/cast_content_window.h

@@ -13,10 +13,6 @@
 #include "content/public/browser/web_contents.h"
 #include "ui/events/event.h"
 
-namespace content {
-class WebContents;
-}
-
 namespace chromecast {
 namespace shell {
 

chromecast/browser/cast_web_view.h

@@ -16,6 +16,7 @@
 #include "chromecast/graphics/cast_window_manager.h"
 #include "content/public/browser/bluetooth_chooser.h"
 #include "content/public/browser/web_contents.h"
+#include "url/gurl.h"
 
 namespace chromecast {