Make constructors recognize char[n] vs. char* and avoid strlen calls.

Make constructors recognize const char[n] vs. char* and avoid strlen calls.

Not an issue for bytestrings, but for widestrings, the compiler doesn't seem to optimize wcslen() calls away.

[Tom Sepez, 2015-12-15 00:20:10]

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

[Tom Sepez, 2015-12-15 00:20:11]

We may need to reconsider this.  Discuss amongst yourselves.

[Tom Sepez, 2015-12-15 00:20:25]

We may need to reconsider this.  Discuss amongst yourselves.

[brucedawson, 2015-12-15 00:45:10]

https://codereview.chromium.org/1114313006/diff/40001/core/include/fxcrt/fx_s...
File core/include/fxcrt/fx_string.h (right):

https://codereview.chromium.org/1114313006/diff/40001/core/include/fxcrt/fx_s...
core/include/fxcrt/fx_string.h:56: : CFX_ByteStringC(ptr, N - 1) { }
I don't think we have any guarantee that this is a literal. It could simply be
an array that is const. This won't happen often because arrays that are only
partially filled cannot (practically speaking) be const, but they can become
const, by passing them to a function which takes a const array and then that
function passing them to CFX_ByteString.