WebView: Create UMA uploader

android_webview/native/aw_metrics_log_uploader.cc

+// 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.
+
+#include "android_webview/native/aw_metrics_log_uploader.h"
+
+#include "android_webview/jni/AwMetricsLogUploader_jni.h"
+#include "base/android/jni_array.h"
+#include "third_party/zlib/google/compression_utils.h"
+
+using base::android::ScopedJavaLocalRef;
+using base::android::ToJavaByteArray;
+
+namespace android_webview {
+
+AwMetricsLogUploader::AwMetricsLogUploader(
+    const base::Callback<void(int)>& on_upload_complete)
+    : on_upload_complete_(on_upload_complete) {}
+
+AwMetricsLogUploader::~AwMetricsLogUploader() {}
+
+void AwMetricsLogUploader::UploadLog(const std::string& compressed_log_data,
+                                     const std::string& log_hash) {
+  // WebView uses the platform logging mechanism instead of the normal UMA
+  // server. The platform mechanism does its own compression, so undo the
+  // previous compression.
+  std::string log_data;
+  compression::GzipUncompress(compressed_log_data, &log_data);

[Alexei Svitkine (slow), 2017/03/29 19:19:17]

I agree about your point about this leaking implementation details from
components/metrics. If you prefer, an option would be to make a wrapper for this
in components/metrics that's called "DecodeLogData" or something like that - and
then this can call it instead of gzip directly.

(Up to you - can also done in a separate CL).

[paulmiller, 2017/03/29 19:52:38]

Okay, I'll do that separately.

+
+  JNIEnv* env = base::android::AttachCurrentThread();
+  ScopedJavaLocalRef<jbyteArray> java_data = ToJavaByteArray(
+      env, reinterpret_cast<const uint8_t*>(log_data.data()), log_data.size());
+  Java_AwMetricsLogUploader_uploadLog(env, java_data);
+
+  // The platform mechanism doesn't provide a response code or any way to handle
+  // failures, so we have nothing to pass to on_upload_complete. Just pass 200
+  // (HTTP OK) and pretend everything is peachy.
+  on_upload_complete_.Run(200);
+}
+
+}  // namespace android_webview