Download: Retrieve display names for all downloads.

This CL fixes a bug that download may disappear on Android Q after
they are completed.

We query and cache the display names from media store only when there
are more than 0 in progress downloads. So the cache might be empty and
we use the cache for completed download as well, which result in
missing display name and download history db recorded being removed.

Also directly check Android version in c++. The current code loads Q
API when loading Java static methods in DownloadCollectionBridge, which
triggers disk read violation on Android P.

Bug: 1106286
Change-Id: I2338a665a2147154ffd20df447fe74b84a8c8738
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2314299
Commit-Queue: Xing Liu <xingliu@chromium.org>
Reviewed-by: Min Qin <qinmin@chromium.org>
Reviewed-by: David Trainor <dtrainor@chromium.org>
Cr-Commit-Position: refs/heads/master@{#791631}

components/download/internal/common/android/download_collection_bridge.cc

@@ -168,12 +168,6 @@ void DownloadCollectionBridge::GetDisplayNamesForDownloads(
   std::move(cb).Run(std::move(result));
 }
 
-// static
-bool DownloadCollectionBridge::NeedToRetrieveDisplayNames() {
-  JNIEnv* env = base::android::AttachCurrentThread();
-  return Java_DownloadCollectionBridge_needToRetrieveDisplayNames(env);
-}
-
 // static
 base::FilePath DownloadCollectionBridge::GetDisplayName(
     const base::FilePath& download_uri) {

components/download/internal/common/android/download_collection_bridge.h

@@ -62,11 +62,6 @@ class COMPONENTS_DOWNLOAD_EXPORT DownloadCollectionBridge {
   static bool RenameDownloadUri(const base::FilePath& download_uri,
                                 const base::FilePath& new_display_name);
 
-  // Whether download display names needs to be retrieved.
-  // TODO(qinmin): move display names to history and in-progress DB.
-  // Can be called on any thread.
-  static bool NeedToRetrieveDisplayNames();
-
   using GetDisplayNamesCallback =
       base::OnceCallback<void(InProgressDownloadManager::DisplayNames)>;
   // Gets the display name for all downloads.

components/download/internal/common/android/java/src/org/chromium/components/download/DownloadCollectionBridge.java

@@ -262,14 +262,6 @@ public class DownloadCollectionBridge {
                 == 1;
     }
 
-    /**
-     * @return  Whether download display names needs to be retrieved.
-     */
-    @CalledByNative
-    private static boolean needToRetrieveDisplayNames() {
-        return isAtLeastQ();
-    }
-
     /**
      * Gets the display names for all downloads
      * @return an array of download Uri and display name pair.

components/download/internal/common/in_progress_download_manager.cc

@@ -30,6 +30,7 @@
 #include "services/network/public/mojom/url_response_head.mojom.h"
 
 #if defined(OS_ANDROID)
+#include "base/android/build_info.h"
 #include "components/download/internal/common/android/download_collection_bridge.h"
 #include "components/download/public/common/download_path_reservation_tracker.h"
 #endif
@@ -574,8 +575,8 @@ void InProgressDownloadManager::OnDBInitialized(
     bool success,
     std::unique_ptr<std::vector<DownloadDBEntry>> entries) {
 #if defined(OS_ANDROID)
-  if (entries->size() > 0 &&
-      DownloadCollectionBridge::NeedToRetrieveDisplayNames()) {
+  // Retrieve display names for all downloads from media store if needed.
+  if (base::android::BuildInfo::GetInstance()->is_at_least_q()) {
     DownloadCollectionBridge::GetDisplayNamesCallback callback =
         base::BindOnce(&InProgressDownloadManager::OnDownloadNamesRetrieved,
                        weak_factory_.GetWeakPtr(), std::move(entries));