[AR][IOS] Adds support for .USDZ file extension for ARKit 3D models

Many static file hosting services do not allow setting the appropriate
content-type when serving files. This CL relaxes the requirement to display
USDZ 3D models with ARQuickLook by checking the file extension in addition
to the content type.

Bug: 958938
Change-Id: I1f1a216d3e4f8bbe660242f5acb2eadef0c57509
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1597121
Commit-Queue: Moe Ahmadi <mahmadi@chromium.org>
Reviewed-by: Eugene But <eugenebut@chromium.org>
Cr-Commit-Position: refs/heads/master@{#657726}

ios/chrome/browser/download/ar_quick_look_tab_helper.mm

@@ -35,7 +35,8 @@ namespace {
 // Returns a suffix for Download.IOSDownloadARModelState histogram for the
 // |download_task|.
 std::string GetMimeTypeSuffix(web::DownloadTask* download_task) {
-  DCHECK(IsUsdzFileFormat(download_task->GetOriginalMimeType()));
+  DCHECK(IsUsdzFileFormat(download_task->GetOriginalMimeType(),
+                          download_task->GetSuggestedFilename()));
   return kUsdzMimeTypeHistogramSuffix;
 }
 
@@ -50,7 +51,8 @@ IOSDownloadARModelState GetHistogramEnum(web::DownloadTask* download_task) {
     return IOSDownloadARModelState::kStarted;
   }
   DCHECK(download_task->IsDone());
-  if (!IsUsdzFileFormat(download_task->GetMimeType())) {
+  if (!IsUsdzFileFormat(download_task->GetMimeType(),
+                        download_task->GetSuggestedFilename())) {
     return IOSDownloadARModelState::kWrongMimeTypeFailure;
   }
   if (download_task->GetHttpCode() == 401 ||
@@ -120,7 +122,8 @@ void ARQuickLookTabHelper::DidFinishDownload() {
   // Inform the delegate only if the download has been successful.
   if (download_task_->GetHttpCode() == 401 ||
       download_task_->GetHttpCode() == 403 || download_task_->GetErrorCode() ||
-      !IsUsdzFileFormat(download_task_->GetMimeType())) {
+      !IsUsdzFileFormat(download_task_->GetMimeType(),
+                        download_task_->GetSuggestedFilename())) {
     return;
   }
 

ios/chrome/browser/download/ar_quick_look_tab_helper_unittest.mm

@@ -36,6 +36,7 @@ const char kHistogramName[] = "Download.IOSDownloadARModelState.USDZ";
 const char kUrl[] = "https://test.test/";
 
 NSString* const kTestSuggestedFileName = @"important_file.zip";
+NSString* const kTestUsdzFileName = @"important_file.usdz";
 
 }  // namespace
 
@@ -64,8 +65,46 @@ class ARQuickLookTabHelperTest : public PlatformTest,
   base::HistogramTester histogram_tester_;
 };
 
-// Tests successfully downloading a USDZ file.
-TEST_P(ARQuickLookTabHelperTest, Success) {
+// Tests successfully downloading a USDZ file with the appropriate extension.
+TEST_F(ARQuickLookTabHelperTest, SuccessFileExtention) {
+  auto task = std::make_unique<web::FakeDownloadTask>(GURL(kUrl), "other");
+  task->SetSuggestedFilename(base::SysNSStringToUTF16(kTestUsdzFileName));
+  web::FakeDownloadTask* task_ptr = task.get();
+  tab_helper()->Download(std::move(task));
+  ASSERT_TRUE(WaitUntilConditionOrTimeout(kWaitForDownloadTimeout, ^{
+    base::RunLoop().RunUntilIdle();
+    return task_ptr->GetState() == web::DownloadTask::State::kInProgress;
+  }));
+  task_ptr->SetDone(true);
+  EXPECT_EQ(1U, delegate().fileURLs.count);
+  EXPECT_TRUE([delegate().fileURLs.firstObject isKindOfClass:[NSURL class]]);
+
+  // Downloaded file should be located in download directory.
+  base::FilePath file =
+      task_ptr->GetResponseWriter()->AsFileWriter()->file_path();
+  base::FilePath download_dir;
+  ASSERT_TRUE(GetDownloadsDirectory(&download_dir));
+  EXPECT_TRUE(download_dir.IsParent(file));
+
+  histogram_tester()->ExpectBucketCount(
+      kHistogramName,
+      static_cast<base::HistogramBase::Sample>(
+          IOSDownloadARModelState::kCreated),
+      1);
+  histogram_tester()->ExpectBucketCount(
+      kHistogramName,
+      static_cast<base::HistogramBase::Sample>(
+          IOSDownloadARModelState::kStarted),
+      1);
+  histogram_tester()->ExpectBucketCount(
+      kHistogramName,
+      static_cast<base::HistogramBase::Sample>(
+          IOSDownloadARModelState::kSuccessful),
+      1);
+}
+
+// Tests successfully downloading a USDZ file with the appropriate content-type.
+TEST_P(ARQuickLookTabHelperTest, SuccessContentType) {
   auto task = std::make_unique<web::FakeDownloadTask>(GURL(kUrl), GetParam());
   task->SetSuggestedFilename(base::SysNSStringToUTF16(kTestSuggestedFileName));
   web::FakeDownloadTask* task_ptr = task.get();

ios/chrome/browser/download/browser_download_service.mm

@@ -111,7 +111,8 @@ void BrowserDownloadService::OnDownloadCreated(
     if (tab_helper) {
       tab_helper->Download(std::move(task));
     }
-  } else if (IsUsdzFileFormat(task->GetMimeType()) &&
+  } else if (IsUsdzFileFormat(task->GetMimeType(),
+                              task->GetSuggestedFilename()) &&
              download::IsUsdzPreviewEnabled()) {
     ARQuickLookTabHelper* tab_helper =
         ARQuickLookTabHelper::FromWebState(web_state);

ios/chrome/browser/download/browser_download_service_unittest.mm

@@ -7,6 +7,7 @@
 #include <vector>
 
 #include "base/macros.h"
+#include "base/strings/utf_string_conversions.h"
 #include "base/test/metrics/histogram_tester.h"
 #include "ios/chrome/browser/browser_state/test_chrome_browser_state.h"
 #import "ios/chrome/browser/download/ar_quick_look_tab_helper.h"
@@ -29,6 +30,7 @@
 
 namespace {
 char kUrl[] = "https://test.test/";
+char kUsdzFileName[] = "important_file.usdz";
 
 // Substitutes real TabHelper for testing.
 template <class TabHelper>
@@ -157,6 +159,30 @@ TEST_F(BrowserDownloadServiceTest, PkPassMimeType) {
       1);
 }
 
+// Tests that BrowserDownloadService uses ARQuickLookTabHelper for .USDZ
+// extension.
+TEST_F(BrowserDownloadServiceTest, UsdzExtension) {
+  if (!download::IsUsdzPreviewEnabled()) {
+    // Disabled on iOS versions below 12 because QLPreviewController is not
+    // available.
+    return;
+  }
+
+  ASSERT_TRUE(download_controller()->GetDelegate());
+  auto task = std::make_unique<web::FakeDownloadTask>(GURL(kUrl), "other");
+  task->SetSuggestedFilename(base::UTF8ToUTF16(kUsdzFileName));
+  web::DownloadTask* task_ptr = task.get();
+  download_controller()->GetDelegate()->OnDownloadCreated(
+      download_controller(), &web_state_, std::move(task));
+  ASSERT_EQ(1U, ar_quick_look_tab_helper()->tasks().size());
+  EXPECT_EQ(task_ptr, ar_quick_look_tab_helper()->tasks()[0].get());
+  ASSERT_TRUE(download_manager_tab_helper()->tasks().empty());
+  histogram_tester_.ExpectUniqueSample(
+      "Download.IOSDownloadMimeType",
+      static_cast<base::HistogramBase::Sample>(DownloadMimeTypeResult::Other),
+      1);
+}
+
 // Tests that BrowserDownloadService uses ARQuickLookTabHelper for USDZ Mime
 // type.
 TEST_F(BrowserDownloadServiceTest, UsdzMimeType) {

ios/chrome/browser/download/usdz_mime_type.cc

@@ -4,11 +4,18 @@
 
 #include "ios/chrome/browser/download/usdz_mime_type.h"
 
+#include "base/files/file_path.h"
+#include "base/strings/utf_string_conversions.h"
+
+char kUsdzFileExntension[] = ".usdz";
 char kUsdzMimeType[] = "model/vnd.usdz+zip";
 char kLegacyUsdzMimeType[] = "model/usd";
 char kLegacyPixarUsdzMimeType[] = "model/vnd.pixar.usd";
 
-bool IsUsdzFileFormat(const std::string& mime_type) {
+bool IsUsdzFileFormat(const std::string& mime_type,
+                      const base::string16& suggested_filename) {
   return mime_type == kUsdzMimeType || mime_type == kLegacyUsdzMimeType ||
-         mime_type == kLegacyPixarUsdzMimeType;
+         mime_type == kLegacyPixarUsdzMimeType ||
+         base::FilePath(base::UTF16ToUTF8(suggested_filename))
+             .MatchesExtension(kUsdzFileExntension);
 }

ios/chrome/browser/download/usdz_mime_type.h

@@ -7,6 +7,8 @@
 
 #include <string>
 
+#include "base/strings/string16.h"
+
 // Universal Scene Description file format used to represent 3D models.
 // See https://www.iana.org/assignments/media-types/model/vnd.usdz+zip
 extern char kUsdzMimeType[];
@@ -14,6 +16,10 @@ extern char kUsdzMimeType[];
 extern char kLegacyUsdzMimeType[];
 extern char kLegacyPixarUsdzMimeType[];
 
-bool IsUsdzFileFormat(const std::string& mime_type);
+// Returns whether the content-type or the file extension match those of a USDZ
+// 3D model. The file extension is checked in addition to the content-type since
+// many static file hosting services do not allow setting the content-type.
+bool IsUsdzFileFormat(const std::string& mime_type,
+                      const base::string16& suggested_filename);
 
 #endif  // IOS_CHROME_BROWSER_DOWNLOAD_USDZ_MIME_TYPE_H_