[Crash Reporting] Implement a more direct bridge for extracting logcat output.

components/crash/android/java/src/org/chromium/components/crash/browser/CrashDumpManager.java

Index: components/crash/android/java/src/org/chromium/components/crash/browser/CrashDumpManager.java
diff --git a/components/crash/android/java/src/org/chromium/components/crash/browser/CrashDumpManager.java b/components/crash/android/java/src/org/chromium/components/crash/browser/CrashDumpManager.java
new file mode 100644
index 0000000000000000000000000000000000000000..495556181de78a8b14f72f034a5e6d8bd082d26d
--- /dev/null
+++ b/components/crash/android/java/src/org/chromium/components/crash/browser/CrashDumpManager.java
@@ -0,0 +1,80 @@
+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.components.crash.browser;
+
+import org.chromium.base.Log;
+import org.chromium.base.ThreadUtils;
+import org.chromium.base.annotations.CalledByNative;
+
+import java.io.File;
+
+/**
+ * A Java-side bridge for continuing the upload processing for child process crash minidumps.
+ */
+public class CrashDumpManager {
+    private static final String TAG = "CrashDumpManager";
+
+    /**
+     * An interface for providing a callback that will try to upload a minidump. The callback should
+     * be registered on, and will be run on, the UI thread.
+     */
+    public interface UploadMinidumpCallback { public void tryToUploadMinidump(File minidump); }
+
+    /**
+     * The globally registered callback for uploading minidumps, or null if no callback has been
+     * registered yet.
+     */
+    private static UploadMinidumpCallback sCallback;
+
+    /**
+     * Registers a callback for uploading minidumps. May be called at most once, and only on the UI
+     * thread.
+     *
+     * @param callback The callback to trigger when a new minidump is generated by a child process.
+     */
+    public static void registerUploadCallback(UploadMinidumpCallback callback) {
+        ThreadUtils.assertOnUiThread();
+        assert sCallback == null;
+        sCallback = callback;
+    }
+
+    /**
+     * Attempts to upload the specified child process minidump (or a no-op if no observer has been
+     * registered).
+     *
+     * @param minidumpPath The file path for the generated minidump.
+     */
+    @CalledByNative
+    public static void tryToUploadMinidump(String minidumpPath) {
+        // The C++ code that calls into this method should be running on a background thread. It's
+        // important to be off the UI thread for the file operations done below.
+        ThreadUtils.assertOnBackgroundThread();
+
+        if (minidumpPath == null) {
+            Log.e(TAG, "Minidump path should be non-null! Bailing...");
+            return;
+        }
+
+        final File minidump = new File(minidumpPath);
+        if (!minidump.exists() || !minidump.isFile()) {
+            Log.e(TAG,
+                    "Minidump path '" + minidumpPath
+                            + "' should describe a file that exists! Bailing...");
+            return;
+        }
+
+        // The callback should only be accessed on the UI thread.
+        ThreadUtils.postOnUiThread(new Runnable() {
+            @Override
+            public void run() {
+                if (sCallback == null) {
+                    Log.w(TAG, "Ignoring crash observed before a callback was registered...");
+                    return;
+                }
+                sCallback.tryToUploadMinidump(minidump);
+            }
+        });
+    }
+}