Reland "[SH-Blink] Create TextFragmentSelectorGenerator with page."

This is a reland of d43884e1

Fix memory leak issue by cleaning selection_range member in
TextFragmentSelectorGenerator on DocumentDetached.
Reverted version is in patchset 1.

Original change's description:
> [SH-Blink] Create TextFragmentSelectorGenerator with page.
>
> Create TextFragmentSelectorGenerator with page and set selection
> information when context menu is shown.
> This is done so that Java code can just call the GenerateSelector
> function without any arguments and generation can happen for the latest
> selected text.
>
> Follow-up CL
> https://chromium-review.googlesource.com/c/chromium/src/+/2341662
> will connect to browser-side component.
>
> Bug: 1102382
> Change-Id: I5574f5b40e5a74bef56698e2de5a9b1fea17e0d0
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2340734
> Reviewed-by: Yoshifumi Inoue <yosin@chromium.org>
> Reviewed-by: David Bokan <bokan@chromium.org>
> Commit-Queue: Gayane Petrosyan <gayane@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#797256}

Bug: 1102382
Change-Id: If05b8e643627f4851dced45ce02cd78b7fa87fde
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2354304Reviewed-by: Yoshifumi Inoue <yosin@chromium.org>
Reviewed-by: David Bokan <bokan@chromium.org>
Commit-Queue: Gayane Petrosyan <gayane@chromium.org>
Cr-Commit-Position: refs/heads/master@{#798643}

third_party/blink/renderer/core/page/context_menu_controller.cc

@@ -41,6 +41,7 @@
 #include "third_party/blink/renderer/core/dom/node.h"
 #include "third_party/blink/renderer/core/editing/editing_tri_state.h"
 #include "third_party/blink/renderer/core/editing/editor.h"
+#include "third_party/blink/renderer/core/editing/ephemeral_range.h"
 #include "third_party/blink/renderer/core/editing/frame_selection.h"
 #include "third_party/blink/renderer/core/editing/ime/input_method_controller.h"
 #include "third_party/blink/renderer/core/editing/selection_controller.h"
@@ -69,6 +70,7 @@
 #include "third_party/blink/renderer/core/page/context_menu_provider.h"
 #include "third_party/blink/renderer/core/page/focus_controller.h"
 #include "third_party/blink/renderer/core/page/page.h"
+#include "third_party/blink/renderer/core/page/scrolling/text_fragment_selector_generator.h"
 #include "third_party/blink/renderer/platform/exported/wrapped_resource_response.h"
 
 namespace blink {
@@ -246,6 +248,17 @@ bool ContextMenuController::ShowContextMenu(LocalFrame* frame,
             PhysicalOffset(FlooredIntPoint(point)));
   }
 
+  // Store text selection when it happens as it might be cleared when the
+  // browser will request |TextFragmentSelectorGenerator| to generator selector.
+  if (!selected_frame->Selection().SelectedText().IsEmpty()) {
+    VisibleSelectionInFlatTree selection =
+        selected_frame->Selection().ComputeVisibleSelectionInFlatTree();
+    EphemeralRangeInFlatTree selection_range(selection.Start(),
+                                             selection.End());
+    page_->GetTextFragmentSelectorGenerator().UpdateSelection(selected_frame,
+                                                              selection_range);
+  }
+
   WebContextMenuData data;
   data.mouse_position = selected_frame->View()->FrameToViewport(
       result.RoundedPointInInnerNodeFrame());

third_party/blink/renderer/core/page/page.cc

@@ -75,6 +75,7 @@
 #include "third_party/blink/renderer/core/page/scoped_page_pauser.h"
 #include "third_party/blink/renderer/core/page/scrolling/overscroll_controller.h"
 #include "third_party/blink/renderer/core/page/scrolling/scrolling_coordinator.h"
+#include "third_party/blink/renderer/core/page/scrolling/text_fragment_selector_generator.h"
 #include "third_party/blink/renderer/core/page/scrolling/top_document_root_scroller_controller.h"
 #include "third_party/blink/renderer/core/page/spatial_navigation_controller.h"
 #include "third_party/blink/renderer/core/page/validation_message_client_impl.h"
@@ -225,7 +226,9 @@ Page::Page(PageClients& page_clients)
       next_related_page_(this),
       prev_related_page_(this),
       autoplay_flags_(0),
-      web_text_autosizer_page_info_({0, 0, 1.f}) {
+      web_text_autosizer_page_info_({0, 0, 1.f}),
+      text_fragment_selector_generator_(
+          MakeGarbageCollected<TextFragmentSelectorGenerator>()) {
   DCHECK(!AllPages().Contains(this));
   AllPages().insert(this);
 
@@ -340,6 +343,7 @@ LocalFrame* Page::DeprecatedLocalMainFrame() const {
 
 void Page::DocumentDetached(Document* document) {
   pointer_lock_controller_->DocumentDetached(document);
+  text_fragment_selector_generator_->DocumentDetached(document);
   context_menu_controller_->DocumentDetached(document);
   if (validation_message_client_)
     validation_message_client_->DocumentDetached(*document);
@@ -914,6 +918,7 @@ void Page::Trace(Visitor* visitor) const {
   visitor->Trace(plugins_changed_observers_);
   visitor->Trace(next_related_page_);
   visitor->Trace(prev_related_page_);
+  visitor->Trace(text_fragment_selector_generator_);
   Supplementable<Page>::Trace(visitor);
 }
 

third_party/blink/renderer/core/page/page.h

@@ -75,6 +75,7 @@ class PageScaleConstraintsSet;
 class PluginData;
 class PluginsChangedObserver;
 class PointerLockController;
+class TextFragmentSelectorGenerator;
 class ScopedPagePauser;
 class ScrollingCoordinator;
 class ScrollbarTheme;
@@ -356,6 +357,10 @@ class CORE_EXPORT Page final : public GarbageCollected<Page>,
 
   static void PrepareForLeakDetection();
 
+  TextFragmentSelectorGenerator& GetTextFragmentSelectorGenerator() const {
+    return *text_fragment_selector_generator_;
+  }
+
  private:
   friend class ScopedPagePauser;
 
@@ -477,6 +482,8 @@ class CORE_EXPORT Page final : public GarbageCollected<Page>,
 
   WebScopedVirtualTimePauser history_navigation_virtual_time_pauser_;
 
+  const Member<TextFragmentSelectorGenerator> text_fragment_selector_generator_;
+
   DISALLOW_COPY_AND_ASSIGN(Page);
 };
 

third_party/blink/renderer/core/page/scrolling/text_fragment_selector_generator.cc

@@ -15,27 +15,31 @@ namespace blink {
 constexpr int kExactTextMaxChars = 300;
 constexpr int kNoContextMinChars = 20;
 
-TextFragmentSelectorGenerator::TextFragmentSelectorGenerator(
-    LocalFrame* frame,
-    base::OnceCallback<void(const TextFragmentSelector&)> callback)
-    : frame_(frame), callback_(std::move(callback)) {}
-
-// TextFragmentSelectorGenerator is responsible for generating text fragment
-// selectors that have a unique match.
-void TextFragmentSelectorGenerator::GenerateSelector(
+void TextFragmentSelectorGenerator::UpdateSelection(
+    LocalFrame* selection_frame,
     const EphemeralRangeInFlatTree& selection_range) {
+  selection_frame_ = selection_frame;
+  selection_range_ = MakeGarbageCollected<Range>(
+      selection_range.GetDocument(),
+      ToPositionInDOMTree(selection_range.StartPosition()),
+      ToPositionInDOMTree(selection_range.EndPosition()));
+}
+
+void TextFragmentSelectorGenerator::GenerateSelector() {
+  EphemeralRangeInFlatTree ephemeral_range(selection_range_);
+
   const TextFragmentSelector kInvalidSelector(
       TextFragmentSelector::SelectorType::kInvalid);
 
   Node& start_first_block_ancestor =
       FindBuffer::GetFirstBlockLevelAncestorInclusive(
-          *selection_range.StartPosition().AnchorNode());
+          *ephemeral_range.StartPosition().AnchorNode());
   Node& end_first_block_ancestor =
       FindBuffer::GetFirstBlockLevelAncestorInclusive(
-          *selection_range.EndPosition().AnchorNode());
+          *ephemeral_range.EndPosition().AnchorNode());
 
   if (!start_first_block_ancestor.isSameNode(&end_first_block_ancestor))
-    std::move(callback_).Run(kInvalidSelector);
+    NotifySelectorReady(kInvalidSelector);
 
   // TODO(gayane): If same node, need to check if start and end are interrupted
   // by a block. Example: <div>start of the selection <div> sub block </div>end
@@ -43,16 +47,16 @@ void TextFragmentSelectorGenerator::GenerateSelector(
 
   // TODO(gayane): Move selection start and end to contain full words.
 
-  String selected_text = PlainText(selection_range);
+  String selected_text = PlainText(ephemeral_range);
 
   if (selected_text.length() < kNoContextMinChars ||
       selected_text.length() > kExactTextMaxChars)
-    std::move(callback_).Run(kInvalidSelector);
+    NotifySelectorReady(kInvalidSelector);
 
   selector_ = std::make_unique<TextFragmentSelector>(
       TextFragmentSelector::SelectorType::kExact, selected_text, "", "", "");
   TextFragmentFinder finder(*this, *selector_);
-  finder.FindMatch(*frame_->GetDocument());
+  finder.FindMatch(*selection_frame_->GetDocument());
 }
 
 void TextFragmentSelectorGenerator::DidFindMatch(
@@ -60,16 +64,36 @@ void TextFragmentSelectorGenerator::DidFindMatch(
     const TextFragmentAnchorMetrics::Match match_metrics,
     bool is_unique) {
   if (is_unique) {
-    std::move(callback_).Run(*selector_);
+    NotifySelectorReady(*selector_);
   } else {
     // TODO(gayane): Should add more range and/or context.
-    std::move(callback_).Run(
+    NotifySelectorReady(
         TextFragmentSelector(TextFragmentSelector::SelectorType::kInvalid));
   }
 }
 
+void TextFragmentSelectorGenerator::SetCallbackForTesting(
+    base::OnceCallback<void(const TextFragmentSelector&)> callback) {
+  callback_for_tests_ = std::move(callback);
+}
+
+void TextFragmentSelectorGenerator::NotifySelectorReady(
+    const TextFragmentSelector& selector) {
+  if (!callback_for_tests_.is_null())
+    std::move(callback_for_tests_).Run(selector);
+}
+
+void TextFragmentSelectorGenerator::DocumentDetached(Document* document) {
+  if (selection_range_ && selection_range_->OwnerDocument() == *document) {
+    selection_range_->Dispose();
+    selection_range_ = nullptr;
+    selection_frame_ = nullptr;
+  }
+}
+
 void TextFragmentSelectorGenerator::Trace(Visitor* visitor) const {
-  visitor->Trace(frame_);
+  visitor->Trace(selection_frame_);
+  visitor->Trace(selection_range_);
 }
 
 }  // namespace blink

third_party/blink/renderer/core/page/scrolling/text_fragment_selector_generator.h

@@ -13,28 +13,48 @@ namespace blink {
 
 class LocalFrame;
 
+// TextFragmentSelectorGenerator is responsible for generating text fragment
+// selectors for the user selected text according to spec in
+// https://github.com/WICG/scroll-to-text-fragment#proposed-solution.
+// Generated selectors would be later used to highlight the same
+// text if successfully parsed by |TextFragmentAnchor |. Generation will be
+// triggered when users request "link to text" for the selected text.
 class CORE_EXPORT TextFragmentSelectorGenerator final
     : public GarbageCollected<TextFragmentSelectorGenerator>,
       public TextFragmentFinder::Client {
  public:
-  TextFragmentSelectorGenerator(
-      LocalFrame* frame,
-      base::OnceCallback<void(const TextFragmentSelector&)> callback);
+  explicit TextFragmentSelectorGenerator() = default;
+
+  // Sets the frame and range of the current selection.
+  void UpdateSelection(LocalFrame* selection_frame,
+                       const EphemeralRangeInFlatTree& selection_range);
 
-  void GenerateSelector(const EphemeralRangeInFlatTree& selection_range);
+  // Generates selector for current selection.
+  void GenerateSelector();
 
   // TextFragmentFinder::Client interface
   void DidFindMatch(const EphemeralRangeInFlatTree& match,
                     const TextFragmentAnchorMetrics::Match match_metrics,
                     bool is_unique) override;
 
+  // Sets the callback used for notifying test results of |GenerateSelector|.
+  void SetCallbackForTesting(
+      base::OnceCallback<void(const TextFragmentSelector&)> callback);
+
+  // Notifies the results of |GenerateSelector|.
+  void NotifySelectorReady(const TextFragmentSelector& selector);
+
+  void DocumentDetached(Document* document);
+
   void Trace(Visitor*) const;
 
  private:
-  Member<LocalFrame> frame_;
-  base::OnceCallback<void(const TextFragmentSelector&)> callback_;
+  Member<LocalFrame> selection_frame_;
+  Member<Range> selection_range_;
   std::unique_ptr<TextFragmentSelector> selector_;
 
+  base::OnceCallback<void(const TextFragmentSelector&)> callback_for_tests_;
+
   DISALLOW_COPY_AND_ASSIGN(TextFragmentSelectorGenerator);
 };
 

third_party/blink/renderer/core/page/scrolling/text_fragment_selector_generator_test.cc

@@ -41,10 +41,13 @@ TEST_F(TextFragmentSelectorGeneratorTest, ExactTextSelector) {
         callback_called = true;
       });
 
-  TextFragmentSelectorGenerator generator(GetDocument().GetFrame(),
-                                          std::move(callback));
-  generator.GenerateSelector(
+  TextFragmentSelectorGenerator generator;
+  generator.UpdateSelection(
+      GetDocument().GetFrame(),
       ToEphemeralRangeInFlatTree(EphemeralRange(selected_start, selected_end)));
+  generator.SetCallbackForTesting(std::move(callback));
+  generator.GenerateSelector();
+
   EXPECT_TRUE(callback_called);
 }
 
@@ -69,10 +72,13 @@ TEST_F(TextFragmentSelectorGeneratorTest, ExactTextWithNestedTextNodes) {
         callback_called = true;
       });
 
-  TextFragmentSelectorGenerator generator(GetDocument().GetFrame(),
-                                          std::move(callback));
-  generator.GenerateSelector(
+  TextFragmentSelectorGenerator generator;
+  generator.UpdateSelection(
+      GetDocument().GetFrame(),
       ToEphemeralRangeInFlatTree(EphemeralRange(selected_start, selected_end)));
+  generator.SetCallbackForTesting(std::move(callback));
+  generator.GenerateSelector();
+
   EXPECT_TRUE(callback_called);
 }
 
@@ -96,10 +102,13 @@ TEST_F(TextFragmentSelectorGeneratorTest, ExactTextWithExtraSpace) {
         callback_called = true;
       });
 
-  TextFragmentSelectorGenerator generator(GetDocument().GetFrame(),
-                                          std::move(callback));
-  generator.GenerateSelector(
+  TextFragmentSelectorGenerator generator;
+  generator.UpdateSelection(
+      GetDocument().GetFrame(),
       ToEphemeralRangeInFlatTree(EphemeralRange(selected_start, selected_end)));
+  generator.SetCallbackForTesting(std::move(callback));
+  generator.GenerateSelector();
+
   EXPECT_TRUE(callback_called);
 }
 
@@ -125,10 +134,13 @@ TEST_F(TextFragmentSelectorGeneratorTest, MultiblockSelection) {
         callback_called = true;
       });
 
-  TextFragmentSelectorGenerator generator(GetDocument().GetFrame(),
-                                          std::move(callback));
-  generator.GenerateSelector(
+  TextFragmentSelectorGenerator generator;
+  generator.UpdateSelection(
+      GetDocument().GetFrame(),
       ToEphemeralRangeInFlatTree(EphemeralRange(selected_start, selected_end)));
+  generator.SetCallbackForTesting(std::move(callback));
+  generator.GenerateSelector();
+
   EXPECT_TRUE(callback_called);
 }