[LayoutNG] Avoid calling HandleOverflow multiple times

This patch eliminates the call to |HandleOverflow| when the
|NGLineBreaker| state is 'overflow'.

r701601 (crrev.com/c/1826063) added the 'overflow' state to
|NGLineBreaker|. This state makes the `trailing' state more
efficient, but when multiple text runs appear without any
break opportunities in the 'overflow' state, the change
added a call to |HandleOverflow| on each text run.

Bug: 1010487
Change-Id: I608b704a9b65f905e6b57c245ea8f5dac7194c64
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1838791Reviewed-by: Yoshifumi Inoue <yosin@chromium.org>
Commit-Queue: Koji Ishii <kojii@chromium.org>
Cr-Commit-Position: refs/heads/master@{#702942}

third_party/blink/renderer/core/layout/ng/inline/ng_line_breaker.cc

@@ -362,13 +362,6 @@ void NGLineBreaker::BreakLine(
       continue;
     }
 
-    // If |state_| is overflow, break at the earliest break opportunity.
-    const NGInlineItemResults& item_results = line_info->Results();
-    if (state_ == LineBreakState::kOverflow &&
-        CanBreakAfterLast(item_results)) {
-      state_ = LineBreakState::kTrailing;
-    }
-
     // If we reach at the end of the block, this is the last line.
     DCHECK_LE(item_index_, items.size());
     if (item_index_ == items.size()) {
@@ -376,6 +369,13 @@ void NGLineBreaker::BreakLine(
       return;
     }
 
+    // If |state_| is overflow, break at the earliest break opportunity.
+    const NGInlineItemResults& item_results = line_info->Results();
+    if (UNLIKELY(state_ == LineBreakState::kOverflow &&
+                 CanBreakAfterLast(item_results))) {
+      state_ = LineBreakState::kTrailing;
+    }
+
     // Handle trailable items first. These items may not be break before.
     // They (or part of them) may also overhang the available width.
     const NGInlineItem& item = items[item_index_];
@@ -576,6 +576,12 @@ void NGLineBreaker::HandleText(const NGInlineItem& item,
     }
 
     DCHECK_EQ(break_result, kOverflow);
+    if (UNLIKELY(state_ == LineBreakState::kOverflow &&
+                 item_result->shape_result)) {
+      if (item_result->can_break_after)
+        state_ = LineBreakState::kTrailing;
+      return;
+    }
     return HandleOverflow(line_info);
   }