Fix #1 for multiple request issue (both POST and GET) after activating the onhttpequiv approach. 
There's a ton going on here. Brief summary: I'm introducing a caching layer for top level page requests that we then use again when switching the document from mshtml to cf. 

Also in this change list: 
* Removing the previous way of shifting the document moniker 
over to the worker thread when a new chrome document is 
created. Instead we use a request cache object. 
* Refactoring the part of the Bho class that offered access 
to it via TLS. This was needed for better testability but 
also makes (imho) the separation clearer and will possibly 
help in the future if we don't have a Bho object. 
* Added a bit of logging that I'd prefer to keep in there until we're confident enough with onhttpequiv. 
* Enabling two previously disabled tests (the ones I added for multiple requests) 
* Adding several more unit tests for the new code. 
Review URL: http://codereview.chromium.org/668187

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@41495 0039d316-1c4b-4281-b951-d872f2087c98
24 files changed