Make contenteditable="false" element as atomic node for selection motion

LayoutTests/editing/selection/mixed-editability-3-expected.txt

-EDITING DELEGATE: shouldBeginEditingInDOMRange:range from 0 of DIV > BODY > HTML > #document to 3 of DIV > BODY > HTML > #document
-EDITING DELEGATE: webViewDidBeginEditing:WebViewDidBeginEditingNotification
-EDITING DELEGATE: webViewDidChangeSelection:WebViewDidChangeSelectionNotification
-EDITING DELEGATE: shouldEndEditingInDOMRange:range from 0 of DIV > BODY > HTML > #document to 3 of DIV > BODY > HTML > #document
-EDITING DELEGATE: webViewDidEndEditing:WebViewDidEndEditingNotification
-EDITING DELEGATE: shouldBeginEditingInDOMRange:range from 0 of TD > TR > TBODY > TABLE > DIV > BODY > HTML > #document to 1 of TD > TR > TBODY > TABLE > DIV > BODY > HTML > #document
-EDITING DELEGATE: webViewDidBeginEditing:WebViewDidBeginEditingNotification
-EDITING DELEGATE: webViewDidChangeSelection:WebViewDidChangeSelectionNotification
-layer at (0,0) size 800x600
-  RenderView at (0,0) size 800x600
-layer at (0,0) size 800x600
-  RenderBlock {HTML} at (0,0) size 800x600
-    RenderBody {BODY} at (8,8) size 784x584
-      RenderBlock {P} at (0,0) size 784x36
-        RenderText {#text} at (0,0) size 754x36
-          text run at (0,0) width 459: "This tests moving the caret forward through content of mixed editability. "
-          text run at (459,0) width 295: "The caret should move down one line from the"
-          text run at (0,18) width 470: "editable piece to the editable piece that's embedded in a non-editable piece."
-      RenderBlock {DIV} at (0,52) size 784x64
-        RenderBlock (anonymous) at (0,0) size 784x18
-          RenderText {#text} at (0,0) size 49x18
-            text run at (0,0) width 49: "editable"
-        RenderTable {TABLE} at (0,18) size 59x28 [border: (1px outset #808080)]
-          RenderTableSection {TBODY} at (1,1) size 57x26
-            RenderTableRow {TR} at (0,2) size 57x22
-              RenderTableCell {TD} at (2,2) size 53x22 [border: (1px inset #808080)] [r=0 c=0 rs=1 cs=1]
-                RenderText {#text} at (2,2) size 49x18
-                  text run at (2,2) width 49: "editable"
-        RenderBlock (anonymous) at (0,46) size 784x18
-          RenderText {#text} at (0,0) size 49x18
-            text run at (0,0) width 49: "editable"
-caret: position 0 of child 0 {#text} of child 0 {TD} of child 0 {TR} of child 0 {TBODY} of child 1 {TABLE} of child 2 {DIV} of body
+This tests moving the caret forward through content of mixed editability. The caret should not be in non-editable piece.
+
+On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".
+
+
+Move forward line x 1
+PASS selection.anchorNode == '[object Text]' is true
+PASS selection.anchorOffset is 0
+Move backward line x 1
+PASS selection.anchorNode == '[object Text]' is true
+PASS selection.anchorOffset is 0
+Move forward line x 1
+PASS selection.anchorNode == '[object Text]' is true
+PASS selection.anchorOffset is 10
+Move backward line x 1
+PASS selection.anchorNode == '[object Text]' is true
+PASS selection.anchorOffset is 10
+PASS successfullyParsed is true
+
+TEST COMPLETE
+