Replace magic constant with kFixedSize

When calling certain functions in GridLayout a resize
parameter is passed, defining how much the layout should
resize.
Most often it is passed as 0 or 1. Sometimes 100 (which
is assumed to be the same as 1) and sometimes 0.5.

This commit defines the variable kFixedSize = 0.f
in grid_layout.h and remove every local defintion of
the variables. The magic constant are replaced by this
variable. The replacements are:
0, 0.f and 0.0f becomes kFixedSize (0.f)

This commit affects chrome/browser/ui.

Bug: 854186
Change-Id: I287b1b38350a2dce2bd6e02cc871e82e0a5d89db
Reviewed-on: https://chromium-review.googlesource.com/1106159
Reviewed-by: Dan Erat <derat@chromium.org>
Reviewed-by: Sadrul Chowdhury <sadrul@chromium.org>
Reviewed-by: Bret Sepulveda <bsep@chromium.org>
Commit-Queue: Oscar Johansson <oscarj@opera.com>
Cr-Commit-Position: refs/heads/master@{#570693}
54 files changed