[Offline Pages] Adds Rappor metrics measuring what domains are saved & viewed.

components/offline_pages/offline_page_model.cc

Index: components/offline_pages/offline_page_model.cc
diff --git a/components/offline_pages/offline_page_model.cc b/components/offline_pages/offline_page_model.cc
index 8c2e652c5f8e192094ba0a239e5d1891e32e6151..74590685e518988a353173c16fed1393db3dae01 100644
--- a/components/offline_pages/offline_page_model.cc
+++ b/components/offline_pages/offline_page_model.cc
@@ -11,6 +11,7 @@
 #include "base/files/file_util.h"
 #include "base/location.h"
 #include "base/logging.h"
+#include "base/memory/weak_ptr.h"

[fgorski, 2016/05/13 17:49:18]

this is already in .h file.

 #include "base/metrics/histogram_macros.h"
 #include "base/optional.h"
 #include "base/rand_util.h"
@@ -22,6 +23,8 @@
 #include "components/offline_pages/offline_page_item.h"
 #include "components/offline_pages/offline_page_storage_manager.h"
 #include "components/offline_pages/proto/offline_pages.pb.h"
+#include "components/rappor/rappor_service.h"
+#include "components/rappor/rappor_utils.h"
 #include "url/gurl.h"
 
 using ArchiverResult = offline_pages::OfflinePageArchiver::ArchiverResult;
@@ -105,6 +108,16 @@ void EnsureArchivesDirCreated(const base::FilePath& archives_dir) {
   CHECK(base::CreateDirectory(archives_dir));
 }
 
+// Record a sample for the OfflinePages.SavedPage rappor metric.
+void SampleOfflinePageURL(
+    const GURL& url,
+    const base::WeakPtr<rappor::RapporService>& rappor_service) {
+  if (rappor_service && url.is_valid()) {
+    rappor::SampleDomainAndRegistryFromGURL(rappor_service.get(),
+                                            "OfflinePages.SavedPage", url);
+  }
+}
+
 }  // namespace
 
 // static
@@ -119,6 +132,7 @@ OfflinePageModel::OfflinePageModel()
 OfflinePageModel::OfflinePageModel(
     std::unique_ptr<OfflinePageMetadataStore> store,
     const base::FilePath& archives_dir,
+    base::WeakPtr<rappor::RapporService> rappor_service,
     const scoped_refptr<base::SequencedTaskRunner>& task_runner)
     : store_(std::move(store)),
       archives_dir_(archives_dir),
@@ -126,6 +140,7 @@ OfflinePageModel::OfflinePageModel(
       task_runner_(task_runner),
       policy_controller_(new ClientPolicyController()),
       storage_manager_(new OfflinePageStorageManager(this)),
+      rappor_service_(rappor_service),
       weak_ptr_factory_(this) {
   task_runner_->PostTaskAndReply(
       FROM_HERE, base::Bind(EnsureArchivesDirCreated, archives_dir_),
@@ -159,6 +174,8 @@ void OfflinePageModel::SavePage(const GURL& url,
 
   DCHECK(archiver.get());
 
+  SampleOfflinePageURL(url, rappor_service_);
+
   int64_t offline_id = GenerateOfflineId();
 
   archiver->CreateArchive(