[Partial reland] Replace GzipUncompress() with DecodeLogDataToProto().

Original description:
Replace GzipUncompress calls with DecodeLogDataToProto.

Also, remove "ukm::", where applicable, from ukm_service_unittest.cc

Bug: 1086910

Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2222521Reviewed-by: Tommy Nyquist <nyquist@chromium.org>
Reviewed-by: Steven Holte <holte@chromium.org>
Commit-Queue: Caitlin Fischer <caitlinfischer@google.com>
Cr-Original-Commit-Position: refs/heads/master@{#777137}
Change-Id: Ia59944a291b095755f5b9cb889f6c16b5388a704
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2248750
Cr-Commit-Position: refs/heads/master@{#780252}

components/metrics/DEPS

@@ -21,3 +21,9 @@ include_rules = [
   "-net",
   "+url"
 ]
+
+specific_include_rules = {
+  "log_decoder\.cc": [
+    "+third_party/protobuf/src/google/protobuf",
+  ],
+}

components/metrics/log_decoder.cc

@@ -4,6 +4,7 @@
 
 #include "components/metrics/log_decoder.h"
 
+#include "third_party/protobuf/src/google/protobuf/message_lite.h"
 #include "third_party/zlib/google/compression_utils.h"
 
 namespace metrics {
@@ -14,12 +15,12 @@ bool DecodeLogData(const std::string& compressed_log_data,
 }
 
 bool DecodeLogDataToProto(const std::string& compressed_log_data,
-                          ChromeUserMetricsExtension* uma_proto) {
+                          google::protobuf::MessageLite* proto) {
   std::string log_data;
   if (!DecodeLogData(compressed_log_data, &log_data))
     return false;
 
-  return uma_proto->ParseFromString(log_data);
+  return proto->ParseFromString(log_data);
 }
 
 }  // namespace metrics

components/metrics/log_decoder.h

@@ -7,7 +7,13 @@
 
 #include <string>
 
-#include "third_party/metrics_proto/chrome_user_metrics_extension.pb.h"
+namespace google {
+namespace protobuf {
+
+class MessageLite;
+
+}  // namespace protobuf
+}  // namespace google
 
 namespace metrics {
 
@@ -18,10 +24,10 @@ namespace metrics {
 bool DecodeLogData(const std::string& compressed_log_data,
                    std::string* log_data);
 
-// Decodes |compressed_log_data| and populates |uma_proto| with the decompressed
-// log data. Returns true on success and false on failure.
+// Decodes |compressed_log_data| and populates |proto| with the decompressed log
+// data. Returns true on success and false on failure.
 bool DecodeLogDataToProto(const std::string& compressed_log_data,
-                          ChromeUserMetricsExtension* uma_proto);
+                          google::protobuf::MessageLite* proto);
 
 }  // namespace metrics
 

components/metrics/test/demographic_metrics_test_utils.cc

@@ -7,12 +7,12 @@
 #include "base/strings/stringprintf.h"
 #include "base/time/default_clock.h"
 #include "base/time/default_tick_clock.h"
+#include "components/metrics/log_decoder.h"
 #include "components/sync/base/pref_names.h"
 #include "components/sync/base/user_demographics.h"
 #include "components/sync/engine_impl/loopback_server/persistent_unique_client_entity.h"
 #include "components/sync/protocol/sync.pb.h"
 #include "third_party/metrics_proto/chrome_user_metrics_extension.pb.h"
-#include "third_party/zlib/google/compression_utils.h"
 
 namespace metrics {
 namespace test {
@@ -94,18 +94,11 @@ bool HasUnsentLogs(MetricsService* metrics_service) {
 // Returns an UMA log if the MetricsService has a staged log.
 std::unique_ptr<ChromeUserMetricsExtension> GetLastUmaLog(
     MetricsService* metrics_service) {
-  // Decompress the staged log.
-  std::string uncompressed_log;
-  if (!compression::GzipUncompress(
-          metrics_service->LogStoreForTest()->staged_log(),
-          &uncompressed_log)) {
-    return nullptr;
-  }
-
-  // Deserialize and return the log.
+  // Decompress and deserialize the staged log.
   std::unique_ptr<ChromeUserMetricsExtension> log =
       std::make_unique<ChromeUserMetricsExtension>();
-  if (!log->ParseFromString(uncompressed_log)) {
+  if (!DecodeLogDataToProto(metrics_service->LogStoreForTest()->staged_log(),
+                            log.get())) {
     return nullptr;
   }
   return log;

components/ukm/BUILD.gn

@@ -136,6 +136,5 @@ static_library("ukm_test_helper") {
     "//components/metrics",
     "//services/metrics/public/cpp:metrics_cpp",
     "//third_party/metrics_proto",
-    "//third_party/zlib/google:compression_utils",
   ]
 }

components/ukm/ukm_service.cc

@@ -111,6 +111,7 @@ void PurgeExtensionDataFromUnsentLogStore(
     const std::string& compressed_log_data =
         ukm_log_store->GetLogAtIndex(index);
     std::string uncompressed_log_data;
+    // TODO(crbug/1086910): Use the utilities in log_decoder.h instead.
     const bool uncompress_successful = compression::GzipUncompress(
         compressed_log_data, &uncompressed_log_data);
     DCHECK(uncompress_successful);

components/ukm/ukm_test_helper.cc

@@ -10,8 +10,8 @@
 #include "base/feature_list.h"
 #include "base/run_loop.h"
 #include "base/stl_util.h"
+#include "components/metrics/log_decoder.h"
 #include "components/metrics/unsent_log_store.h"
-#include "third_party/zlib/google/compression_utils.h"
 
 namespace ukm {
 
@@ -51,13 +51,8 @@ std::unique_ptr<Report> UkmTestHelper::GetUkmReport() {
   if (!log_store->has_staged_log())
     return nullptr;
 
-  std::string uncompressed_log_data;
-  if (!compression::GzipUncompress(log_store->staged_log(),
-                                   &uncompressed_log_data))
-    return nullptr;
-
   std::unique_ptr<ukm::Report> report = std::make_unique<ukm::Report>();
-  if (!report->ParseFromString(uncompressed_log_data))
+  if (!metrics::DecodeLogDataToProto(log_store->staged_log(), report.get()))
     return nullptr;
 
   return report;