Make UtilityProcessHost non public

Removes UtilityProcessHost from content/public and renames
UtilityprocessHostImpl to UtilityProcessHost.
Now that all use cases of UtilityProcessHost have been replaced by
using services (but for the PowerMonitor browser tests), this will
prevent further forking of process bypassing the service manager.

Bug: 775677
Change-Id: I2107271a54e4ab3141102a5c4fbcce4ea21915dd
Reviewed-on: https://chromium-review.googlesource.com/961496
Reviewed-by: Avi Drissman <[email protected]>
Reviewed-by: John Abd-El-Malek <[email protected]>
Reviewed-by: Ken Rockot <[email protected]>
Commit-Queue: Jay Civelli <[email protected]>
Cr-Commit-Position: refs/heads/master@{#543238}
diff --git a/content/browser/BUILD.gn b/content/browser/BUILD.gn
index 7ada79c1..1723a36 100644
--- a/content/browser/BUILD.gn
+++ b/content/browser/BUILD.gn
@@ -1630,8 +1630,8 @@
     "tracing/tracing_ui.h",
     "url_loader_factory_getter.cc",
     "url_loader_factory_getter.h",
-    "utility_process_host_impl.cc",
-    "utility_process_host_impl.h",
+    "utility_process_host.cc",
+    "utility_process_host.h",
     "wake_lock/wake_lock_context_host.cc",
     "wake_lock/wake_lock_context_host.h",
     "web_contents/aura/gesture_nav_simple.cc",