More targeted resource-switching mechanism for SVG selection painting

third_party/WebKit/Source/core/paint/SVGInlineTextBoxPainter.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/paint/SVGInlineTextBoxPainter.h"
 
 #include "core/editing/Editor.h"
 #include "core/editing/markers/DocumentMarkerController.h"
 #include "core/frame/LocalFrame.h"
 #include "core/layout/LayoutTheme.h"
@@ skipping 503 matching lines @@
   // selection.
   bool paint_selected_text_only = paint_info.phase == kPaintPhaseSelection;
   if (start_position > 0 && !paint_selected_text_only) {
     PaintFlags flags;
     if (SetupTextPaint(paint_info, style, resource_mode, flags))
       PaintText(paint_info, text_run, fragment, 0, start_position, flags);
   }
 
   // Draw text using selection style from the start to the end position of the
   // selection.
-  if (style != selection_style) {
-    StyleDifference diff;
-    diff.SetNeedsPaintInvalidationObject();
-    SVGResourcesCache::ClientStyleChanged(&ParentInlineLayoutObject(), diff,
-                                          selection_style);
-  }
+  {
+    SVGResourcesCache::TemporaryStyleScope scope(ParentInlineLayoutObject(),
+                                                 style, selection_style);
 
-  PaintFlags flags;
-  if (SetupTextPaint(paint_info, selection_style, resource_mode, flags))
-    PaintText(paint_info, text_run, fragment, start_position, end_position,
-              flags);
-
-  if (style != selection_style) {
-    StyleDifference diff;
-    diff.SetNeedsPaintInvalidationObject();
-    SVGResourcesCache::ClientStyleChanged(&ParentInlineLayoutObject(), diff,
-                                          style);
+    PaintFlags flags;
+    if (SetupTextPaint(paint_info, selection_style, resource_mode, flags)) {
+      PaintText(paint_info, text_run, fragment, start_position, end_position,
+                flags);
+    }
   }
 
   // Eventually draw text using regular style from the end position of the
   // selection to the end of the current chunk part.
   if (end_position < static_cast<int>(fragment.length) &&
       !paint_selected_text_only) {
     PaintFlags flags;
     if (SetupTextPaint(paint_info, style, resource_mode, flags)) {
       PaintText(paint_info, text_run, fragment, end_position, fragment.length,
                 flags);
@@ skipping 111 matching lines @@
     }
     FloatRect fragment_rect = svg_inline_text_box_.SelectionRectForTextFragment(
         fragment, text_match_info.start_position, text_match_info.end_position,
         style);
     paint_info.context.SetFillColor(color);
     paint_info.context.FillRect(fragment_rect);
   }
 }
 
 }  // namespace blink