Merge 110 | ax_ui: chromium hangs on user input when dealing with lar…

…ge documents

SnapToMaxTextOffsetIfBeyond can be a heavy operation when triggered
on ax position creation. Disable it for now since it regresses the user
experience harsh. Later, all callers should be reworked, the method call
removed and only the IsValid() assertion should be left in place.

This is a partial revert of crrev.com/c/3810575, and todo-marked tests
from crrev.com/c/3961717 which was landed on top of the original
culprit CL.

Regressed by: crrev.com/c/3810575

(cherry picked from commit 5685924)

Bug: 1401591
Bug: 1396198
Change-Id: I448cdc4135a362f708882c0223a01507a6dbb7b3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4126876
Reviewed-by: Aaron Leventhal <aleventhal@chromium.org>
Commit-Queue: Aaron Leventhal <aleventhal@chromium.org>
Cr-Original-Commit-Position: refs/heads/main@{#1088332}
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4134030
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Cr-Commit-Position: refs/branch-heads/5481@{#132}
Cr-Branched-From: 130f3e4-refs/heads/main@{#1084008}

ui/accessibility/ax_node_position_unittest.cc

@@ -9234,9 +9234,11 @@ TEST_F(AXPositionTest,
                                      ax::mojom::TextAffinity::kDownstream);
   ASSERT_NE(nullptr, text_position);
   ASSERT_TRUE(text_position->IsTextPosition());
+  // TODO: the created position is invalid, it should be a null position
+  // instead.
   test_position = text_position->AsLeafTextPositionBeforeCharacter();
   EXPECT_NE(nullptr, test_position);
-  EXPECT_TRUE(test_position->IsNullPosition());
+  EXPECT_FALSE(test_position->IsNullPosition());
 }
 
 TEST_F(AXPositionTest, AsLeafTextPositionAfterCharacter) {

ui/accessibility/ax_position.h

@@ -2554,7 +2554,11 @@ class AXPosition {
         // position were at the start of the inline text box for "Line two".
 
         const int max_text_offset = MaxTextOffset();
-        DCHECK_LE(text_offset_, max_text_offset);
+
+        // TODO(crbug.com/1404289): temporary disabled until ax position
+        // autocorrection issue is fixed.
+        // DCHECK_LE(text_offset_, max_text_offset);
+
         const int max_text_offset_in_parent =
             IsEmbeddedObjectInParent()
                 ? AXNode::kEmbeddedObjectCharacterLengthUTF16
@@ -4527,11 +4531,13 @@ class AXPosition {
         << "Creating a position without an anchor is disallowed:\n"
         << ToDebugString();
 
-    // TODO(accessibility) Remove this line and let the below IsValid()
+    // TODO(crbug.com/1404289) Remove this line and let the below IsValid()
     // assertion get triggered instead. We shouldn't be creating test positions
     // with offsets that are too large. This seems to occur when the anchor node
     // is ignored, and leads to a number of failing tests.
-    SnapToMaxTextOffsetIfBeyond();
+    // Comment this line out as a known performance culprit (also see
+    // crbug.com/1401591).
+    // SnapToMaxTextOffsetIfBeyond();
 
 #if defined(AX_EXTRA_MAC_NODES)
     // Temporary hack to constrain child index when extra mac nodes are present.
@@ -4547,8 +4553,13 @@ class AXPosition {
     }
 #endif
 
-    SANITIZER_CHECK(IsValid()) << "Creating invalid positions is disallowed:\n"
-                               << ToDebugString();
+    // TODO(crbug.com/1404289) see TODO above.
+    // Also look for the failures in
+    // AXPositionTest.AsLeafTextPositionBeforeCharacterIncludingGeneratedNewlines,
+    // AXPlatformNodeTextRangeProviderTest.TestNormalizeTextRangeForceSameAnchorOnDegenerateRange.
+    // SANITIZER_CHECK(IsValid()) << "Creating invalid positions is
+    // disallowed:\n"
+    //                            << ToDebugString();
   }
 
   int AnchorChildCount() const {

ui/accessibility/platform/ax_platform_node_textrangeprovider_win_unittest.cc

@@ -6438,9 +6438,11 @@ TEST_F(AXPlatformNodeTextRangeProviderTest,
 
   EXPECT_EQ(*normalized_start, *normalized_start);
 
-  EXPECT_TRUE(normalized_start->AtStartOfAnchor());
+  // TODO: the start position is wrong.
+  EXPECT_FALSE(normalized_start->AtStartOfAnchor());
+  EXPECT_EQ(3, normalized_start->anchor_id());
+
   EXPECT_TRUE(normalized_end->AtStartOfAnchor());
-  EXPECT_EQ(7, normalized_start->anchor_id());
   EXPECT_EQ(7, normalized_end->anchor_id());
 }