[Offline pages]: Move logic for whether to consider the DocumentAvailableInMainFrame signal to the …

components/offline_pages/core/snapshot_controller.cc

Index: components/offline_pages/core/snapshot_controller.cc
diff --git a/components/offline_pages/core/snapshot_controller.cc b/components/offline_pages/core/snapshot_controller.cc
index c683a1a9b1056a0e039db12074f9bb48cd36c51b..9d62297fb7b62b60c99628df69417f082f799ce5 100644
--- a/components/offline_pages/core/snapshot_controller.cc
+++ b/components/offline_pages/core/snapshot_controller.cc
@@ -11,6 +11,8 @@
 #include "components/offline_pages/core/offline_page_feature.h"
 
 namespace {
+const bool kDocumentAvailableTriggersSnapshot = true;
+
 // Default delay, in milliseconds, between the main document parsed event and
 // snapshot. Note: this snapshot might not occur if the OnLoad event and
 // OnLoad delay elapses first to trigger a final snapshot.
@@ -18,7 +20,8 @@ const int64_t kDefaultDelayAfterDocumentAvailableMs = 7000;
 
 // Default delay, in milliseconds, between the main document OnLoad event and
 // snapshot.
-const int64_t kDelayAfterDocumentOnLoadCompletedMs = 1000;
+const int64_t kDelayAfterDocumentOnLoadCompletedMsForeground = 1000;
+const int64_t kDelayAfterDocumentOnLoadCompletedMsBackground = 2000;
 
 // Delay for testing to keep polling times reasonable.
 const int64_t kDelayForTests = 0;
@@ -27,25 +30,42 @@ const int64_t kDelayForTests = 0;
 
 namespace offline_pages {
 
-SnapshotController::SnapshotController(
+// static
+std::unique_ptr<SnapshotController>
+SnapshotController::CreateForForegroundOfflining(
+    const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
+    SnapshotController::Client* client) {
+  return std::unique_ptr<SnapshotController>(new SnapshotController(
+      task_runner, client, kDefaultDelayAfterDocumentAvailableMs,
+      kDelayAfterDocumentOnLoadCompletedMsForeground,
+      kDocumentAvailableTriggersSnapshot));
+}
+
+// static
+std::unique_ptr<SnapshotController>
+SnapshotController::CreateForBackgroundOfflining(
     const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
-    SnapshotController::Client* client)
-    : SnapshotController(task_runner,
-                         client,
-                         kDefaultDelayAfterDocumentAvailableMs,
-                         kDelayAfterDocumentOnLoadCompletedMs) {}
+    SnapshotController::Client* client) {
+  return std::unique_ptr<SnapshotController>(new SnapshotController(
+      task_runner, client, kDefaultDelayAfterDocumentAvailableMs,
+      kDelayAfterDocumentOnLoadCompletedMsBackground,
+      !kDocumentAvailableTriggersSnapshot));
+}
 
 SnapshotController::SnapshotController(
     const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
     SnapshotController::Client* client,
     int64_t delay_after_document_available_ms,
-    int64_t delay_after_document_on_load_completed_ms)
+    int64_t delay_after_document_on_load_completed_ms,
+    bool document_available_triggers_snapshot)
     : task_runner_(task_runner),
       client_(client),
       state_(State::READY),
       delay_after_document_available_ms_(delay_after_document_available_ms),
       delay_after_document_on_load_completed_ms_(
           delay_after_document_on_load_completed_ms),
+      document_available_triggers_snapshot_(
+          document_available_triggers_snapshot),
       weak_ptr_factory_(this) {
   if (offline_pages::ShouldUseTestingSnapshotDelay()) {
     delay_after_document_available_ms_ = kDelayForTests;
@@ -75,13 +95,16 @@ void SnapshotController::PendingSnapshotCompleted() {
 }
 
 void SnapshotController::DocumentAvailableInMainFrame() {
-  DCHECK_EQ(PageQuality::POOR, current_page_quality_);
-  // Post a delayed task to snapshot.
-  task_runner_->PostDelayedTask(
-      FROM_HERE, base::Bind(&SnapshotController::MaybeStartSnapshot,
-                            weak_ptr_factory_.GetWeakPtr(),
-                            PageQuality::FAIR_AND_IMPROVING),
-      base::TimeDelta::FromMilliseconds(delay_after_document_available_ms_));
+  if (document_available_triggers_snapshot_) {
+    DCHECK_EQ(PageQuality::POOR, current_page_quality_);
+    // Post a delayed task to snapshot.
+    task_runner_->PostDelayedTask(
+        FROM_HERE,
+        base::Bind(&SnapshotController::MaybeStartSnapshot,
+                   weak_ptr_factory_.GetWeakPtr(),
+                   PageQuality::FAIR_AND_IMPROVING),
+        base::TimeDelta::FromMilliseconds(delay_after_document_available_ms_));
+  }
 }
 
 void SnapshotController::DocumentOnLoadCompletedInMainFrame() {