Split up the if checks in ComputedStyle to make them easy to generate

This patch splits up the iff checks in the diffing function
ComputedStyle::UpdatePropertySpecificDifferences with the intention of
making it easy to generate with the macro fieldwise_diff created here:
https://codereview.chromium.org/2858863002

As can be seen in the try bot runs this has no perf impact

BUG=710938

Review-Url: https://codereview.chromium.org/2855873003
Cr-Commit-Position: refs/heads/master@{#469268}

third_party/WebKit/Source/core/style/ComputedStyle.cpp

@@ -1017,27 +1017,39 @@ void ComputedStyle::UpdatePropertySpecificDifferences(
         rare_non_inherited_data_->perspective_origin_ !=
             other.rare_non_inherited_data_->perspective_origin_)
       diff.SetTransformChanged();
+  }
 
+  if (rare_non_inherited_data_.Get() != other.rare_non_inherited_data_.Get()) {
     if (rare_non_inherited_data_->opacity !=
         other.rare_non_inherited_data_->opacity)
       diff.SetOpacityChanged();
+  }
 
+  if (rare_non_inherited_data_.Get() != other.rare_non_inherited_data_.Get()) {
     if (rare_non_inherited_data_->filter_ !=
         other.rare_non_inherited_data_->filter_)
       diff.SetFilterChanged();
+  }
 
+  if (rare_non_inherited_data_.Get() != other.rare_non_inherited_data_.Get()) {
     if (!rare_non_inherited_data_->ShadowDataEquivalent(
             *other.rare_non_inherited_data_.Get()))
       diff.SetNeedsRecomputeOverflow();
+  }
 
+  if (rare_non_inherited_data_.Get() != other.rare_non_inherited_data_.Get()) {
     if (rare_non_inherited_data_->backdrop_filter_ !=
         other.rare_non_inherited_data_->backdrop_filter_)
       diff.SetBackdropFilterChanged();
+  }
 
+  if (rare_non_inherited_data_.Get() != other.rare_non_inherited_data_.Get()) {
     if (!rare_non_inherited_data_->ReflectionDataEquivalent(
             *other.rare_non_inherited_data_.Get()))
       diff.SetFilterChanged();
+  }
 
+  if (rare_non_inherited_data_.Get() != other.rare_non_inherited_data_.Get()) {
     if (!rare_non_inherited_data_->outline_.VisuallyEqual(
             other.rare_non_inherited_data_->outline_))
       diff.SetNeedsRecomputeOverflow();
@@ -1053,43 +1065,46 @@ void ComputedStyle::UpdatePropertySpecificDifferences(
         HasSimpleUnderlineInternal() != other.HasSimpleUnderlineInternal() ||
         visual_data_->text_decoration != other.visual_data_->text_decoration) {
       diff.SetTextDecorationOrColorChanged();
-    } else if (rare_non_inherited_data_.Get() !=
-                   other.rare_non_inherited_data_.Get() &&
-               (rare_non_inherited_data_->text_decoration_style_ !=
-                    other.rare_non_inherited_data_->text_decoration_style_ ||
-                rare_non_inherited_data_->text_decoration_color_ !=
-                    other.rare_non_inherited_data_->text_decoration_color_ ||
-                rare_non_inherited_data_->visited_link_text_decoration_color_ !=
-                    other.rare_non_inherited_data_
-                        ->visited_link_text_decoration_color_)) {
-      diff.SetTextDecorationOrColorChanged();
-    } else if (rare_inherited_data_.Get() != other.rare_inherited_data_.Get() &&
-               (rare_inherited_data_->TextFillColor() !=
-                    other.rare_inherited_data_->TextFillColor() ||
-                rare_inherited_data_->TextStrokeColor() !=
-                    other.rare_inherited_data_->TextStrokeColor() ||
-                rare_inherited_data_->TextEmphasisColor() !=
-                    other.rare_inherited_data_->TextEmphasisColor() ||
-                rare_inherited_data_->VisitedLinkTextFillColor() !=
-                    other.rare_inherited_data_->VisitedLinkTextFillColor() ||
-                rare_inherited_data_->VisitedLinkTextStrokeColor() !=
-                    other.rare_inherited_data_->VisitedLinkTextStrokeColor() ||
-                rare_inherited_data_->VisitedLinkTextEmphasisColor() !=
-                    other.rare_inherited_data_
-                        ->VisitedLinkTextEmphasisColor() ||
-                rare_inherited_data_->text_emphasis_fill !=
-                    other.rare_inherited_data_->text_emphasis_fill ||
-                rare_inherited_data_->text_underline_position_ !=
-                    other.rare_inherited_data_->text_underline_position_ ||
-                rare_inherited_data_->text_decoration_skip_ !=
-                    other.rare_inherited_data_->text_decoration_skip_ ||
-                rare_inherited_data_->applied_text_decorations !=
-                    other.rare_inherited_data_->applied_text_decorations ||
-                rare_inherited_data_->CaretColor() !=
-                    other.rare_inherited_data_->CaretColor() ||
-                rare_inherited_data_->VisitedLinkCaretColor() !=
-                    other.rare_inherited_data_->VisitedLinkCaretColor())) {
-      diff.SetTextDecorationOrColorChanged();
+    } else {
+      if (rare_non_inherited_data_.Get() !=
+              other.rare_non_inherited_data_.Get() &&
+          (rare_non_inherited_data_->text_decoration_style_ !=
+               other.rare_non_inherited_data_->text_decoration_style_ ||
+           rare_non_inherited_data_->text_decoration_color_ !=
+               other.rare_non_inherited_data_->text_decoration_color_ ||
+           rare_non_inherited_data_->visited_link_text_decoration_color_ !=
+               other.rare_non_inherited_data_
+                   ->visited_link_text_decoration_color_)) {
+        diff.SetTextDecorationOrColorChanged();
+      } else {
+        if (rare_inherited_data_.Get() != other.rare_inherited_data_.Get() &&
+            (rare_inherited_data_->TextFillColor() !=
+                 other.rare_inherited_data_->TextFillColor() ||
+             rare_inherited_data_->TextStrokeColor() !=
+                 other.rare_inherited_data_->TextStrokeColor() ||
+             rare_inherited_data_->TextEmphasisColor() !=
+                 other.rare_inherited_data_->TextEmphasisColor() ||
+             rare_inherited_data_->VisitedLinkTextFillColor() !=
+                 other.rare_inherited_data_->VisitedLinkTextFillColor() ||
+             rare_inherited_data_->VisitedLinkTextStrokeColor() !=
+                 other.rare_inherited_data_->VisitedLinkTextStrokeColor() ||
+             rare_inherited_data_->VisitedLinkTextEmphasisColor() !=
+                 other.rare_inherited_data_->VisitedLinkTextEmphasisColor() ||
+             rare_inherited_data_->text_emphasis_fill !=
+                 other.rare_inherited_data_->text_emphasis_fill ||
+             rare_inherited_data_->text_underline_position_ !=
+                 other.rare_inherited_data_->text_underline_position_ ||
+             rare_inherited_data_->text_decoration_skip_ !=
+                 other.rare_inherited_data_->text_decoration_skip_ ||
+             rare_inherited_data_->applied_text_decorations !=
+                 other.rare_inherited_data_->applied_text_decorations ||
+             rare_inherited_data_->CaretColor() !=
+                 other.rare_inherited_data_->CaretColor() ||
+             rare_inherited_data_->VisitedLinkCaretColor() !=
+                 other.rare_inherited_data_->VisitedLinkCaretColor())) {
+          diff.SetTextDecorationOrColorChanged();
+        }
+      }
     }
   }