android: Fix assert in LibraryLoader

The zygote can only use the system linker for loading library as it
cannot communicate with the browser process at all. Relax the assert
that was not aware of zygote.

Bug: 1035101
Change-Id: If88e09224992aff5e28c3b540d232b6f38fbd16f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1973215
Commit-Queue: Bo <boliu@chromium.org>
Commit-Queue: Benoit L <lizeb@chromium.org>
Commit-Queue: Andrew Grieve <agrieve@chromium.org>
Auto-Submit: Bo <boliu@chromium.org>
Reviewed-by: Benoit L <lizeb@chromium.org>
Reviewed-by: Andrew Grieve <agrieve@chromium.org>
Cr-Commit-Position: refs/heads/master@{#726042}

base/android/java/src/org/chromium/base/library_loader/LibraryLoader.java

@@ -293,14 +293,14 @@ public class LibraryLoader {
         synchronized (mLock) {
             setLinkerImplementationIfNeededAlreadyLocked();
             if (mUseChromiumLinker) return;
-            preloadAlreadyLocked(appContext.getApplicationInfo());
+            preloadAlreadyLocked(appContext.getApplicationInfo(), false /* inZygote */);
         }
     }
 
-    private void preloadAlreadyLocked(ApplicationInfo appInfo) {
+    private void preloadAlreadyLocked(ApplicationInfo appInfo, boolean inZygote) {
         try (TraceEvent te = TraceEvent.scoped("LibraryLoader.preloadAlreadyLocked")) {
             // Preloader uses system linker, we shouldn't preload if Chromium linker is used.
-            assert !mUseChromiumLinker;
+            assert !mUseChromiumLinker || inZygote;
             if (mLibraryPreloader != null && !mLibraryPreloaderCalled) {
                 mLibraryPreloader.loadLibrary(appInfo);
                 mLibraryPreloaderCalled = true;
@@ -451,9 +451,9 @@ public class LibraryLoader {
 
     @GuardedBy("mLock")
     @SuppressLint("UnsafeDynamicallyLoadedCode")
-    private void loadWithSystemLinkerAlreadyLocked(ApplicationInfo appInfo) {
+    private void loadWithSystemLinkerAlreadyLocked(ApplicationInfo appInfo, boolean inZygote) {
         setEnvForNative();
-        preloadAlreadyLocked(appInfo);
+        preloadAlreadyLocked(appInfo, inZygote);
 
         // If the libraries are located in the zip file, assert that the device API level is M or
         // higher. On devices <=M, the libraries should always be loaded by LegacyLinker.
@@ -500,7 +500,7 @@ public class LibraryLoader {
                 loadWithChromiumLinker(appInfo, library);
             } else {
                 Log.d(TAG, "Loading with the System linker.");
-                loadWithSystemLinkerAlreadyLocked(appInfo);
+                loadWithSystemLinkerAlreadyLocked(appInfo, inZygote);
             }
 
             long stopTime = SystemClock.uptimeMillis();