Get rid of fifteen copies of m_sTimeMap and their initializers.

Get rid of fifteen copies of m_sTimeMap and their initializers.

m_sTimeMap is a global variable with a constructor and destructor, which
is not allowed. This change moves it to a function with a static pointer
so that it is constructed on demand and then leaked, thus avoiding
having startup and shutdown code.

This also fixes a worrisome bug caused by having m_sTimeMap defined in
a header file. Because m_sTimeMap was defined (and marked as static) in
a header file there were fifteen separate copies of it, one for each
source file which included the header file. This could easily lead to
bugs because a timer that was added from one source file would be
invisible to other source files.

Each instance of m_sTimeMap added four entries to the
dump-static-initializers.py report, for a total of sixty, so this fix
significantly cleans up that report.

BUG=441899
R=tsepez@chromium.org

Committed: https://pdfium.googlesource.com/pdfium/+/a975cfae4719986e5ea0ff06a45b91e1cdd042b3

[brucedawson, 2014-12-31 01:17:43]

brucedawson@chromium.org changed reviewers:
+ tsepez@chromium.org

[brucedawson, 2014-12-31 01:17:44]

I think this fix is correct according to the Google style guide and Chrome
examples. Specifically:

http://google-styleguide.googlecode.com/svn/trunk/cppguide.html#Static_and_Gl...

https://groups.google.com/a/chromium.org/forum/#!topic/chromium-dev/p6h3HC8Wro4

If not, please let me know. This will fix the majority of the remaining pdfium
initializers.

[Tom Sepez, 2015-01-05 20:27:09]

A quick search shows some precedent for using this style. LGTM

[brucedawson, 2015-01-05 21:21:51]

Committed patchset #1 (id:1) manually as
a975cfae4719986e5ea0ff06a45b91e1cdd042b3 (presubmit successful).