Make sure EndDrag is called

Created a new ScopedClosureRunner in the beginning of the Drop process
that does the following at function return:

1. Flip the `drag_in_progress_` bit.
2. Run any existing `end_drag_runner_`.

This makes sure that the `drag_in_progress_` bit is flipped even if
the function returns early, signaling EndDrag to run immediately. This
also makes sure the bit is flipped *after* the async
GetVirtualFilesAsTempFiles, making use of the `end_drag_runner_`.

(cherry picked from commit 33fd5bb318)

Bug: b:399044195, b:391019233
Change-Id: Ib4e625fb9edc82bfd5235fcb9443308f7928711d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6354726
Reviewed-by: Achuith Bhandarkar <achuith@chromium.org>
Reviewed-by: Alex Moshchuk <alexmos@chromium.org>
Reviewed-by: Nancy Xiao <nancylanxiao@google.com>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Commit-Queue: Vincent Chiang <vincentchiang@chromium.org>
Cr-Original-Commit-Position: refs/heads/main@{#1433727}
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6369545
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Cr-Commit-Position: refs/branch-heads/7049@{#947}
Cr-Branched-From: 2dab7846d0951a552bdc4f350dad497f986e6fed-refs/heads/main@{#1427262}

content/browser/web_contents/web_contents_view_aura.cc

@@ -376,14 +376,14 @@ WebContentsViewAura::OnPerformingDropContext::OnPerformingDropContext(
     std::unique_ptr<DropData> drop_data,
     DropMetadata drop_metadata,
     std::unique_ptr<ui::OSExchangeData> data,
-    base::ScopedClosureRunner end_drag_runner,
+    base::ScopedClosureRunner drop_exit_cleanup,
     std::optional<gfx::PointF> transformed_pt,
     gfx::PointF screen_pt)
     : target_rwh(target_rwh->GetWeakPtr()),
       drop_data(std::move(drop_data)),
       drop_metadata(drop_metadata),
       data(std::move(data)),
-      end_drag_runner(std::move(end_drag_runner)),
+      drop_exit_cleanup(std::move(drop_exit_cleanup)),
       transformed_pt(std::move(transformed_pt)),
       screen_pt(screen_pt) {}
 
@@ -796,10 +796,6 @@ void WebContentsViewAura::PrepareDropData(
 void WebContentsViewAura::EndDrag(
     base::WeakPtr<RenderWidgetHostImpl> source_rwh_weak_ptr,
     DragOperation op) {
-  // `drag_in_progress_` could still be true, if the `PerformDropCallback()`
-  // terminates early and the `end_drag_runner` runs `EndDrag()` before reaching
-  // the CompleteDrop() call.
-  drag_in_progress_ = false;
   drag_security_info_.OnDragEnded();
 
   if (!web_contents_)
@@ -1555,6 +1551,11 @@ void WebContentsViewAura::CompleteDragExit() {
   current_drag_data_.reset();
 }
 
+void WebContentsViewAura::OnDropExit(
+    base::ScopedClosureRunner end_drag_runner) {
+  drag_in_progress_ = false;
+}
+
 // PerformDropCallback() is called once the user releases the mouse button
 // over this window.  This function completes the drop if possible.  A drop
 // may not be possible for example if the RWH has changed since the user's drag
@@ -1607,7 +1608,11 @@ void WebContentsViewAura::PerformDropCallback(
     std::unique_ptr<ui::OSExchangeData> data,
     base::WeakPtr<RenderWidgetHostViewBase> target,
     std::optional<gfx::PointF> transformed_pt) {
-  base::ScopedClosureRunner end_drag_runner(std::move(end_drag_runner_));
+  // Exit callback to make sure |drag_in_pregress_| is flipped on exit and
+  // |end_drag_runner_| is run after OnGotVirtualFilesAsTempFiles finishes.
+  base::ScopedClosureRunner drop_exit_cleanup(base::BindOnce(
+      &WebContentsViewAura::OnDropExit, weak_ptr_factory_.GetWeakPtr(),
+      std::move(end_drag_runner_)));
 
   if (!target) {
     return;
@@ -1642,7 +1647,7 @@ void WebContentsViewAura::PerformDropCallback(
 
   OnPerformingDropContext drop_context(
       target_rwh, std::move(current_drag_data_), drop_metadata, std::move(data),
-      std::move(end_drag_runner), transformed_pt, screen_pt);
+      std::move(drop_exit_cleanup), transformed_pt, screen_pt);
 
 #if BUILDFLAG(IS_WIN)
   if (ShouldIncludeVirtualFiles(*drop_context.drop_data) &&
@@ -1725,7 +1730,6 @@ WebContentsViewAura::GetDropCallback(const ui::DropTargetEvent& event) {
 }
 
 void WebContentsViewAura::CompleteDrop(OnPerformingDropContext drop_context) {
-  drag_in_progress_ = false;
   web_contents_->Focus();
 
   const int key_modifiers =

content/browser/web_contents/web_contents_view_aura.h

@@ -107,7 +107,7 @@ class CONTENT_EXPORT WebContentsViewAura
                             std::unique_ptr<DropData> drop_data,
                             DropMetadata drop_metadata,
                             std::unique_ptr<ui::OSExchangeData> data,
-                            base::ScopedClosureRunner end_drag_runner,
+                            base::ScopedClosureRunner drop_exit_cleanup,
                             std::optional<gfx::PointF> transformed_pt,
                             gfx::PointF screen_pt);
     OnPerformingDropContext(const OnPerformingDropContext& other) = delete;
@@ -120,7 +120,7 @@ class CONTENT_EXPORT WebContentsViewAura
     std::unique_ptr<DropData> drop_data;
     DropMetadata drop_metadata;
     std::unique_ptr<ui::OSExchangeData> data;
-    base::ScopedClosureRunner end_drag_runner;
+    base::ScopedClosureRunner drop_exit_cleanup;
     std::optional<gfx::PointF> transformed_pt;
     gfx::PointF screen_pt;
   };
@@ -151,6 +151,8 @@ class CONTENT_EXPORT WebContentsViewAura
   FRIEND_TEST_ALL_PREFIXES(WebContentsViewAuraTest, GetDropCallback_Run);
   FRIEND_TEST_ALL_PREFIXES(WebContentsViewAuraTest,
                            DragInProgressFinishesAfterDrop);
+  FRIEND_TEST_ALL_PREFIXES(WebContentsViewAuraTest,
+                           DragInProgressFinishesAfterNoDrop);
   FRIEND_TEST_ALL_PREFIXES(WebContentsViewAuraTest, GetDropCallback_Cancelled);
   FRIEND_TEST_ALL_PREFIXES(
       WebContentsViewAuraTest,
@@ -328,6 +330,10 @@ class CONTENT_EXPORT WebContentsViewAura
       ui::mojom::DragOperation& output_drag_op,
       std::unique_ptr<ui::LayerTreeOwner> drag_image_layer_owner);
 
+  // Run when drop callback completes to ensure |drag_in_progess_| is
+  // flipped to false before EndDrag runs.
+  void OnDropExit(base::ScopedClosureRunner end_drag_runner);
+
   // For unit testing, registers a callback for when a drop operation
   // completes.
   using DropCallbackForTesting =

content/browser/web_contents/web_contents_view_aura_browsertest.cc

@@ -1137,9 +1137,45 @@ IN_PROC_BROWSER_TEST_F(WebContentsViewAuraTest,
 
   delegate->DelayedFinishOnPerformingDrop();
   async_drop_run_loop.Run();
+  EXPECT_EQ(1, drag_dest_delegate_.GetOnDropCalledCount());
+  ASSERT_FALSE(view->drag_in_progress_);
   end_drag_run_loop.Run();
 
+  EXPECT_EQ(drop_target_widget_,
+            RenderWidgetHostImpl::From(contents->GetPrimaryFrameTree()
+                                           .root()
+                                           ->current_frame_host()
+                                           ->GetRenderWidgetHost()));
+}
+
+// This test is the same as `DragInProgressFinishesAfterDrop`, but it tests the
+// scenario where drag_in_progress_ should still be flipped even when drop is
+// blocked.
+IN_PROC_BROWSER_TEST_F(WebContentsViewAuraTest,
+                       DragInProgressFinishesAfterNoDrop) {
+  StartTestWithPage("/simple_page.html");
+  WebContentsImpl* contents = GetWebContentsImpl();
+  WebContentsViewAura* view = GetWebContentsViewAura();
+
+  base::RunLoop async_drop_run_loop;
+  async_drop_closure_ = async_drop_run_loop.QuitClosure();
+
+  base::RunLoop end_drag_run_loop;
+  async_end_drag_closure_ = end_drag_run_loop.QuitClosure();
+  view->end_drag_runner_.ReplaceClosure(base::BindOnce(
+      &WebContentsViewAuraTest::EndDrag, base::Unretained(this)));
+
+  TestWebContentsViewDelegate* delegate =
+      PrepareWebContentsViewForDropTest(/*delegate_allows_drop=*/false);
+  SimulateDragEnterAndDrop(/*document_is_handling_drag=*/true);
+  // `drag_in_progress_` should still be true before `CompleteDrop()` is called.
+  ASSERT_TRUE(view->drag_in_progress_);
+
+  delegate->DelayedFinishOnPerformingDrop();
+  async_drop_run_loop.Run();
+  EXPECT_EQ(0, drag_dest_delegate_.GetOnDropCalledCount());
   ASSERT_FALSE(view->drag_in_progress_);
+  end_drag_run_loop.Run();
 
   EXPECT_EQ(drop_target_widget_,
             RenderWidgetHostImpl::From(contents->GetPrimaryFrameTree()