https://bugs.webkit.org/show_bug.cgi?id=30946
<rdar://problem/7639184>

Reviewed by Adele Peterson.

WebCore: 

Do text insertion and whitespace rebalancing around the insertion in one step so that there's only one layout.
This patch was originally made by Justin Garcia.
        
Test: editing/inserting/rebalance-whitespace-1.html

* editing/CompositeEditCommand.cpp:
(WebCore::CompositeEditCommand::rebalanceWhitespaceAt): No behavior changes here,
just pushed the code that determined the extent of whitespace surrounding a position
to its own helper function.
* editing/InsertTextCommand.cpp:
(WebCore::InsertTextCommand::insertTextIntoNodeAndRebalanceWhitespace): Added.  Find 
whitespace surrounding the insertion position, add the text to insert, rebalance that entire
string, then insert it into the document.
(WebCore::InsertTextCommand::input):
* editing/InsertTextCommand.h:
* editing/htmlediting.cpp:
(WebCore::isWhitespace): Moved from CompositeEditCommand.cpp.
(WebCore::extentOfWhitespaceForRebalancingAt): Moved code from rebalanceWhitespaceAt into this helper
function.  Obtains the offset of the start and end of whitespace around a particular position.
* editing/htmlediting.h:

LayoutTests: 

There are now regular spaces where nbsps were used unnecessarily before.  Also,
multi-character insertions now have their whitespace rebalanced, and this is
reflected in a few tests.

* editing/execCommand/5142012-3-expected.txt:
* editing/inserting/rebalance-whitespace-1-expected.txt: Added.
* editing/inserting/rebalance-whitespace-1.html: Added.
* editing/pasteboard/5521237-expected.txt:
* platform/mac/editing/execCommand/5482023-expected.checksum:
* platform/mac/editing/execCommand/5482023-expected.png: Removed.
* platform/mac/editing/execCommand/5482023-expected.txt:
* platform/mac/editing/execCommand/remove-formatting-2-expected.checksum:
* platform/mac/editing/execCommand/remove-formatting-2-expected.png: Removed.
* platform/mac/editing/execCommand/remove-formatting-expected.checksum:
* platform/mac/editing/execCommand/remove-formatting-expected.png: Removed.
* platform/mac/editing/execCommand/remove-formatting-expected.txt:
* platform/mac/editing/inserting/editable-html-element-expected.checksum:
* platform/mac/editing/inserting/editable-html-element-expected.png: Removed.
* platform/mac/editing/inserting/editable-html-element-expected.txt:
* platform/mac/editing/pasteboard/4989774-expected.checksum:
* platform/mac/editing/pasteboard/4989774-expected.png: Removed.
* platform/mac/editing/pasteboard/4989774-expected.txt:
* platform/mac/editing/selection/4983858-expected.checksum:
* platform/mac/editing/selection/4983858-expected.png: Removed.
* platform/mac/editing/selection/4983858-expected.txt:



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@55263 268f45cc-cd09-0410-ab3c-d52691b4dbfc