1 files changed, 34 insertions, 40 deletions

diff --git a/chromium/third_party/blink/renderer/core/scroll/scrollbar_theme.cc b/chromium/third_party/blink/renderer/core/scroll/scrollbar_theme.cc
index 1478704a8eb..2f8f6dc37aa 100644
--- a/chromium/third_party/blink/renderer/core/scroll/scrollbar_theme.cc
+++ b/chromium/third_party/blink/renderer/core/scroll/scrollbar_theme.cc
@@ -28,9 +28,8 @@
 #include "base/optional.h"
 #include "build/build_config.h"
 #include "cc/input/scrollbar.h"
+#include "third_party/blink/public/common/input/web_mouse_event.h"
 #include "third_party/blink/public/platform/platform.h"
-#include "third_party/blink/public/platform/web_mouse_event.h"
-#include "third_party/blink/public/platform/web_point.h"
 #include "third_party/blink/public/platform/web_rect.h"
 #include "third_party/blink/renderer/core/scroll/scrollbar.h"
 #include "third_party/blink/renderer/core/scroll/scrollbar_theme_overlay_mock.h"
@@ -50,29 +49,37 @@
 namespace blink {
 
 void ScrollbarTheme::Paint(const Scrollbar& scrollbar,
-                           GraphicsContext& graphics_context) {
-  PaintTrackButtonsTickmarks(graphics_context, scrollbar, IntPoint());
+                           GraphicsContext& graphics_context,
+                           const IntPoint& paint_offset) {
+  PaintTrackButtonsTickmarks(graphics_context, scrollbar, paint_offset);
 
-  IntRect thumb_rect = ThumbRect(scrollbar);
-  if (HasThumb(scrollbar))
+  if (HasThumb(scrollbar)) {
+    IntRect thumb_rect = ThumbRect(scrollbar);
+    thumb_rect.MoveBy(paint_offset);
     PaintThumbWithOpacity(graphics_context, scrollbar, thumb_rect);
+  }
 }
 
-ScrollbarPart ScrollbarTheme::HitTest(const Scrollbar& scrollbar,
-                                      const IntPoint& position_in_root_frame) {
-  ScrollbarPart result = kNoPart;
+ScrollbarPart ScrollbarTheme::HitTestRootFramePosition(
+    const Scrollbar& scrollbar,
+    const IntPoint& position_in_root_frame) {
+  if (!AllowsHitTest())
+    return kNoPart;
+
   if (!scrollbar.Enabled())
-    return result;
+    return kNoPart;
 
   IntPoint test_position =
       scrollbar.ConvertFromRootFrame(position_in_root_frame);
   test_position.Move(scrollbar.X(), scrollbar.Y());
+  return HitTest(scrollbar, test_position);
+}
 
+ScrollbarPart ScrollbarTheme::HitTest(const Scrollbar& scrollbar,
+                                      const IntPoint& test_position) {
   if (!scrollbar.FrameRect().Contains(test_position))
     return kNoPart;
 
-  result = kScrollbarBGPart;
-
   IntRect track = TrackRect(scrollbar);
   if (track.Contains(test_position)) {
     IntRect before_thumb_rect;
@@ -81,27 +88,20 @@ ScrollbarPart ScrollbarTheme::HitTest(const Scrollbar& scrollbar,
     SplitTrack(scrollbar, track, before_thumb_rect, thumb_rect,
                after_thumb_rect);
     if (thumb_rect.Contains(test_position))
-      result = kThumbPart;
-    else if (before_thumb_rect.Contains(test_position))
-      result = kBackTrackPart;
-    else if (after_thumb_rect.Contains(test_position))
-      result = kForwardTrackPart;
-    else
-      result = kTrackBGPart;
-  } else if (BackButtonRect(scrollbar, kBackButtonStartPart)
-                 .Contains(test_position)) {
-    result = kBackButtonStartPart;
-  } else if (BackButtonRect(scrollbar, kBackButtonEndPart)
-                 .Contains(test_position)) {
-    result = kBackButtonEndPart;
-  } else if (ForwardButtonRect(scrollbar, kForwardButtonStartPart)
-                 .Contains(test_position)) {
-    result = kForwardButtonStartPart;
-  } else if (ForwardButtonRect(scrollbar, kForwardButtonEndPart)
-                 .Contains(test_position)) {
-    result = kForwardButtonEndPart;
+      return kThumbPart;
+    if (before_thumb_rect.Contains(test_position))
+      return kBackTrackPart;
+    if (after_thumb_rect.Contains(test_position))
+      return kForwardTrackPart;
+    return kTrackBGPart;
   }
-  return result;
+
+  if (BackButtonRect(scrollbar).Contains(test_position))
+    return kBackButtonStartPart;
+  if (ForwardButtonRect(scrollbar).Contains(test_position))
+    return kForwardButtonEndPart;
+
+  return kScrollbarBGPart;
 }
 
 void ScrollbarTheme::PaintScrollCorner(
@@ -312,19 +312,13 @@ void ScrollbarTheme::PaintTrackAndButtons(GraphicsContext& context,
                            DisplayItem::kScrollbarTrackAndButtons);
 
   if (HasButtons(scrollbar)) {
-    IntRect back_button_rect = BackButtonRect(scrollbar, kBackButtonStartPart);
+    IntRect back_button_rect = BackButtonRect(scrollbar);
     back_button_rect.MoveBy(offset);
     PaintButton(context, scrollbar, back_button_rect, kBackButtonStartPart);
 
-    IntRect forward_button_rect =
-        ForwardButtonRect(scrollbar, kForwardButtonEndPart);
+    IntRect forward_button_rect = ForwardButtonRect(scrollbar);
     forward_button_rect.MoveBy(offset);
     PaintButton(context, scrollbar, forward_button_rect, kForwardButtonEndPart);
-
-    // Non-custom scrollbars don't have kBackButtonEndPart and
-    // kForwardButtonStartPart.
-    DCHECK(BackButtonRect(scrollbar, kBackButtonEndPart).IsEmpty());
-    DCHECK(ForwardButtonRect(scrollbar, kForwardButtonStartPart).IsEmpty());
   }
 
   IntRect track_rect = TrackRect(scrollbar);