Revert of Fix webview preloading in zygote. (patchset #1 id:1 of...

Revert of Fix webview preloading in zygote. (patchset #1 id:1 of https://codereview.chromium.org/2583913002/ )

Reason for revert:
Realised after the fact that we can't set the process type because the zygote may spawn renderers for Chrome.

Original issue's description:
> Fix webview preloading in zygote.
>
> We weren't setting the process type, which is fetched via JNI during
> JNI_OnLoad. Set it by constructing the LibraryLoader singleton, but
> don't actually call any methods of LibraryLoader, which need to be on
> the right thread, have a Context, have a CommandLine initialised, and
> other setup we can't (or at least, don't currently) do in the zygote.
>
> BUG=
>
> Committed: https://crrev.com/db6be0f685e774c56eef7d03a8ab19736023d8bb
> Cr-Commit-Position: refs/heads/master@{#439213}

TBR=rsesek@chromium.org,sgurun@chromium.org,torne@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=

Review-Url: https://codereview.chromium.org/2586193002
Cr-Commit-Position: refs/heads/master@{#439446}

android_webview/glue/java/src/com/android/webview/chromium/WebViewChromiumFactoryProvider.java

@@ -309,11 +309,6 @@ public class WebViewChromiumFactoryProvider implements WebViewFactoryProvider {
     }
 
     public static boolean preloadInZygote() {
-        try {
-            LibraryLoader.get(LibraryProcessType.PROCESS_WEBVIEW_CHILD);
-        } catch (ProcessInitException e) {
-            throw new RuntimeException("Failed to init LibraryLoader", e);
-        }
         for (String library : NativeLibraries.LIBRARIES) {
             System.loadLibrary(library);
         }