Remove ComputedStyle::initializeBitDefaults().

Previously, the data members in ComputedStyle were initialized using
a method called initializeBitDefaults(). This was to avoid duplicating
code for the two constructors in ComputedStyle. Now that there is only
one constructor in ComputedStyle (that initializes the initial style),
we can remove this method.

This patch replaces the initializeBitDefaults() method with proper
initializer lists in ComputedStyle, InheritedData and NonInheritedData.
It also removes the initial style tag from the ComputedStyle
constructor since we no longer have to differentiate between two
constructors.

BUG=628043

Review-Url: https://codereview.chromium.org/2755043002
Cr-Commit-Position: refs/heads/master@{#458006}
2 files changed