Move Minidump Uploading IO operations off the UI thread.

components/minidump_uploader/android/java/src/org/chromium/components/minidump_uploader/CrashFileManager.java

Index: components/minidump_uploader/android/java/src/org/chromium/components/minidump_uploader/CrashFileManager.java
diff --git a/components/minidump_uploader/android/java/src/org/chromium/components/minidump_uploader/CrashFileManager.java b/components/minidump_uploader/android/java/src/org/chromium/components/minidump_uploader/CrashFileManager.java
index c45418c38f190cd9af883ea5adf45401d119a4e1..ded0b565ee7ef07b70ac333407bf287f61c850f5 100644
--- a/components/minidump_uploader/android/java/src/org/chromium/components/minidump_uploader/CrashFileManager.java
+++ b/components/minidump_uploader/android/java/src/org/chromium/components/minidump_uploader/CrashFileManager.java
@@ -296,7 +296,7 @@ public class CrashFileManager {
      * Create the crash directory for this file manager unless it exists already.
      * @return true iff the crash directory exists when this method returns.
      */
-    public boolean ensureCrashDirExists() {
+    private boolean ensureCrashDirExists() {
         File crashDir = getCrashDirectory();
         // Call mkdir before isDirectory to ensure that if another thread created the directory
         // just before the call to mkdir, the current thread fails mkdir, but passes isDirectory.
@@ -304,6 +304,13 @@ public class CrashFileManager {
     }
 
     /**
+     * @return whether the crash directory already exists.
+     */
+    public boolean crashDirectoryExists() {
+        return getCrashDirectory().isDirectory();
+    }
+
+    /**
      * Returns all minidump files that could still be uploaded, sorted by modification time stamp.
      * Only returns files that we have tried to upload less than {@param maxTries} number of times.
      */