Add use_apk_split parameter to java_apk.gypi / android_apk (gn)

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

Index: base/android/java/src/org/chromium/base/library_loader/LibraryLoader.java
diff --git a/base/android/java/src/org/chromium/base/library_loader/LibraryLoader.java b/base/android/java/src/org/chromium/base/library_loader/LibraryLoader.java
index 9dc686572d0bb4a5f85b2b74c8fa5d012c6fb480..21fa8296a6b69aaf487ebc075e31b0168e4c05a9 100644
--- a/base/android/java/src/org/chromium/base/library_loader/LibraryLoader.java
+++ b/base/android/java/src/org/chromium/base/library_loader/LibraryLoader.java
@@ -4,8 +4,14 @@
 
 package org.chromium.base.library_loader;
 
+import android.annotation.TargetApi;
 import android.content.Context;
+import android.content.pm.ApplicationInfo;
+import android.content.pm.PackageInfo;
+import android.content.pm.PackageManager;
+import android.content.pm.PackageManager.NameNotFoundException;
 import android.os.AsyncTask;
+import android.os.Build;
 import android.os.SystemClock;
 import android.util.Log;
 
@@ -250,7 +256,7 @@ public class LibraryLoader {
                     // Check if the device supports memory mapping the APK file
                     // with executable permissions.
                     if (context != null) {
-                        apkFilePath = context.getApplicationInfo().sourceDir;
+                        apkFilePath = getLibraryApkPath(context);
                         if (mProbeMapApkWithExecPermission) {
                             mMapApkWithExecPermission = Linker.checkMapExecSupport(apkFilePath);
                         }
@@ -364,6 +370,31 @@ public class LibraryLoader {
         }
     }
 
+    // Returns the path to the .apk that holds the native libraries.
+    // This is either the main .apk, or the abi split apk.
+    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
+    private static String getLibraryApkPath(Context context) {
+        ApplicationInfo appInfo = context.getApplicationInfo();
+        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
+            return appInfo.sourceDir;
+        }
+        PackageManager manager = context.getPackageManager();
+        PackageInfo packageInfo = null;
+        try {
+            packageInfo = manager.getPackageInfo(context.getPackageName(), 0);
+        } catch (NameNotFoundException e) {
+            // Should never happen.
+        }
+        if (packageInfo.splitNames != null) {
+            for (int i = 0; i < packageInfo.splitNames.length; ++i) {
+                if (packageInfo.splitNames[i].startsWith("abi_")) {

[cjhopman, 2015/05/16 01:31:10]

Is the abi_ prefix something enforced by android? If not, I don't think we
should hide this assumption all the way down here.

[agrieve, 2015/05/16 02:21:40]

We name it in our build rules. What would you suggest as an alternative?

[cjhopman, 2015/05/16 02:29:07]

Oh, I just don't like it when our code makes hard to find assumptions about what
the build rules are doing. The very best would be if these assumptions were only
done in like one or two classes or something within a package where they'd be
easy to find.

I don't expect you to go that far, but just making it more obvious that this is
making such an assumption would be nice: maybe move the "abi_" string to a
static field with a comment calling out the assumption, or breaking out the
check to a function with such a comment would make me happy.

[agrieve, 2015/05/17 02:06:10]

Thanks for spelling it out. Brand new to the codebase, so the hand-holding is
appreciated! :)

Discovered there's a PackageUtil class in base, so moved a piece into there, and
moved the name check into it's own function to be even more clear about intent.

+                    return appInfo.splitSourceDirs[i];
+                }
+            }
+        }
+        return appInfo.sourceDir;
+    }
+
     // Load a native shared library with the Chromium linker. If the zip file
     // path is not null, the library is loaded directly from the zip file.
     private void loadLibrary(@Nullable String zipFilePath, String libFilePath) {