Remove SpdyStream::DoLoop().

Upcoming HTTP/2 state machine support will invalidate SpdyStream lifetime
assumptions which DoLoop() is currently making.

R=akalin
BUG=330860

Review URL: https://codereview.chromium.org/149253009

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@249159 0039d316-1c4b-4281-b951-d872f2087c98
Added a basic AttachmentStore interface and fake implementation for use in some forthcoming unit tests. AttachmentStore will likely change a lot in a future CL.

Renamed SyncAttachment to Attachment.

Renamed SyncAttachmentId to AttachmentId.

Added CreateId method to Attachment.

BUG=

Review URL: https://codereview.chromium.org/104813004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@249160 0039d316-1c4b-4281-b951-d872f2087c98
Below pdf tests are flaky on official builders for a long time. Disabling it for now.
1. PDFBrowserTest.Basic
2. PDFBrowserTest.Scroll
3. PDFBrowserTest.FindAndCopy

For more details see these bugs.
http://crbug.com/329912
http://crbug.com/332778
http://crbug.com/79837

BUG=329912,332778,72937

Review URL: https://codereview.chromium.org/133443006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@249161 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 249161