Second attempt at trying to land buggy bho avoidance: http://codereview.chrom...

Second attempt at trying to land buggy bho avoidance: http://codereview.chromium.org/3031009

A different approach to avoid crashes in buggy 3rd party BHOs.This time we're more preceise and only target the buggy components.Behaviour for components that handle browser events correctly, is unchanged even in the presence of buggy DLLs.The core class here is the BuggyBhoTls class and here's the comment for that class:

// Construct an instance of this class on the stack when firing web browser
// events that can be sent to buggy BHOs. This class will intercept those
// BHOs (see list in cc file) and ignore notifications to those components
// for as long as the BuggyBhoTls instance on the stack lives.

TEST=A better fix for bug 44463 but also fixes bug 49373 and a number of crashes that haven't been associated with bug reports yet.
BUG=44463, 49373
Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=53236