More targeted resource-switching mechanism for SVG selection painting

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

Index: third_party/WebKit/Source/core/paint/SVGInlineTextBoxPainter.cpp
diff --git a/third_party/WebKit/Source/core/paint/SVGInlineTextBoxPainter.cpp b/third_party/WebKit/Source/core/paint/SVGInlineTextBoxPainter.cpp
index 67c02561988d3d17728f4b335b02f5e012a64df2..e966865b73ae0c58e90d7c7b2a75ca94c5bf4a61 100644
--- a/third_party/WebKit/Source/core/paint/SVGInlineTextBoxPainter.cpp
+++ b/third_party/WebKit/Source/core/paint/SVGInlineTextBoxPainter.cpp
@@ -521,23 +521,15 @@ void SVGInlineTextBoxPainter::PaintText(const PaintInfo& paint_info,
 
   // 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);
-  }
-
-  PaintFlags flags;
-  if (SetupTextPaint(paint_info, selection_style, resource_mode, flags))
-    PaintText(paint_info, text_run, fragment, start_position, end_position,
-              flags);
+  {
+    SVGResourcesCache::TemporaryStyleScope scope(ParentInlineLayoutObject(),

[chrishtr, 2017/04/28 18:39:23]

How about instead teaching the SVG painting code to paint without a cache
if the styles disagree? Cache key would be LayoutObject+style.

[fs, 2017/04/28 18:59:52]

Yes, that's what I'd like to be able to do eventually (generate a paint without
having to go through a HashMap in the paint server LayoutObject.) We're ways off
from being able to do that though.

[chrishtr, 2017/04/28 19:59:39]

ok

+                                                 style, selection_style);
 
-  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