Change internal plumbing of paint flags (including CssParse) to uint32_t
consistently, to match the type used in the client. This will probably
prevent compiler warnings. Also renames "float" to "double" to avoid
confusion about precision.

Change-Id: I80374712c4067ca9e7711cc2d4ec33c440ab9c7c

Adds pseudo-css properties for scaleX and skewX, as well as paint flags,
and plumb them through to the MinikinPaint abstraction and to Harfbuzz,
to support nontrivial scale and stretch of text.

This is the Minikin part of the fix for bug 15186705 "Usability of the
suggestion strip in recent OTA's is severely reduced"

Change-Id: Ifa60355e086e4691ff92c5d50d84eb7cea0fea95

This patch adds caching for both layouts and for HarfBuzz face objects.
The granularity of the cache for layouts is words, so it splits the
input string at word boundaries (using a heuristic). There are is also
some refactoring to reduce the amount of allocation and copying, and
movement towards properly supporting contexts.

The size of the caches is a fixed number of entries; thus, it is
possible to consume a large amount of memory by filling the cache with
lots of large strings. This should be refined towards a scheme that
bounds the total memory used by the cache.

This patch fixes bug 15237293 "Regression: Measure performance is
significantly slower with minikin".

Change-Id: Ie8176857e2d78656ce5479a7c04969819ef2718d

All major externally accessible objects (especially FontFamily and
FontCollection) are now reference counted. In addition, there is a
global lock intended to make operations thread-safe.

WIP notice: in this version of the patch, not all external API entry
points are protected by the lock. That should be fixed.

Change-Id: I14106196e99eb101e8bf1bcb4b81359759d2086c

This patch improves script run itemization and also exposes metrics
and bounds for layouts. In addition, there is a fair amount of internal
cleanup, including ref counting, and making the MinikinFont abstraction
strong enough to support both FreeType and Skia implementations. There
is also a sample implementation using Skia, in the sample directory.

As part of its functionality, his patch measures the bounds of the
layout and gives access through Layout::GetBounds().  The corresponding
method is not implemented in the FreeType-only implementation of
MinikinFont, so that will probably have to be fixed.

Change-Id: Ib1a3fe9d7c90519ac651fb4aa957848e4bb758ec

The MinikinFont class was missing a destructor. The build error was
not caught because incremental builds didn't see fit to relink after
I deleted one of the source files (that contained the impl of this
destructor).

Change-Id: Ic72d56fe28316cd2b2f808910e34ca6f177a1220

This commit removes the direct dependency on FreeType and replaces it
with a MinikinFont abstraction, which is designed to support both
FreeType and Skia fonts (and possibly others in the future).

Also adds a "total advance" to the Layout, with an API for retrieving
it.

Change-Id: If20f92db9a43fd15b0fe9794b761ba00fb21338c