Remove unused editing related member functions from WebViewClient

LayoutTests/platform/win/editing/inserting/redo-expected.txt

Index: LayoutTests/platform/win/editing/inserting/redo-expected.txt
diff --git a/LayoutTests/platform/win/editing/inserting/redo-expected.txt b/LayoutTests/platform/win/editing/inserting/redo-expected.txt
index 03934e8823cf25d54556a0871ac3560bd76e94c9..43c1c526916be3643129cb71f620e34d370d58b1 100644
--- a/LayoutTests/platform/win/editing/inserting/redo-expected.txt
+++ b/LayoutTests/platform/win/editing/inserting/redo-expected.txt
@@ -1,13 +1,9 @@
-EDITING DELEGATE: shouldBeginEditingInDOMRange:range from 0 of DIV > BODY > HTML > #document to 0 of DIV > BODY > HTML > #document
-EDITING DELEGATE: webViewDidBeginEditing:WebViewDidBeginEditingNotification
 EDITING DELEGATE: webViewDidChangeSelection:WebViewDidChangeSelectionNotification
-EDITING DELEGATE: shouldChangeSelectedDOMRange:range from 0 of DIV > BODY > HTML > #document to 0 of DIV > BODY > HTML > #document toDOMRange:range from 48 of #text > DIV > BODY > HTML > #document to 48 of #text > DIV > BODY > HTML > #document affinity:NSSelectionAffinityDownstream stillSelecting:FALSE
 EDITING DELEGATE: webViewDidChangeSelection:WebViewDidChangeSelectionNotification
 EDITING DELEGATE: webViewDidChange:WebViewDidChangeNotification
 EDITING DELEGATE: webViewDidChangeSelection:WebViewDidChangeSelectionNotification
 EDITING DELEGATE: webViewDidChangeSelection:WebViewDidChangeSelectionNotification
 EDITING DELEGATE: webViewDidChange:WebViewDidChangeNotification
-EDITING DELEGATE: shouldChangeSelectedDOMRange:range from 0 of DIV > BODY > HTML > #document to 0 of DIV > BODY > HTML > #document toDOMRange:range from 48 of #text > DIV > BODY > HTML > #document to 48 of #text > DIV > BODY > HTML > #document affinity:NSSelectionAffinityDownstream stillSelecting:FALSE
 EDITING DELEGATE: webViewDidChangeSelection:WebViewDidChangeSelectionNotification
 EDITING DELEGATE: webViewDidChange:WebViewDidChangeNotification
 layer at (0,0) size 800x600