This patch adds a LineBreaker class to Minikin, which will be used for
computing line breaks in StaticLayout. The version in this patch
contains basically the same functionality that existed before, but
hopefully better performance and an interface that's suitable for more
sophisticated paragraph layout.

Note that this version contains a high quality strategy, which mostly
works but doesn't respect varying line width.

Change-Id: I02485d58b1e52856296a72cdd4efd963bc572933

Adds a "HyphenEdit" field to the Minikin Paint object, which represents
an edit to the text to add a hyphen (and, in the future, other edits to
support nonstandard hyphenation).

Change-Id: Ib4ee690b0fe2137e1d1e2c9251e5526b274ec3a7

Previously, HarfBuzz's default fallback to compatibility
decompositions resulted in Mathematical Alphanumeric Symbols getting
rendered as normal letters and digits when there was no font
available to render them. This patch disables that fallback, to
ensure they are displayed as tofus.

Based on a patch by Behdad Esfahbod.

Bug: 19202569
Change-Id: I357f172302448d4ab0b24efc86119f1977b5996b

* commit '79298c34':
  Remove hardcoded ICU include paths.

* commit '5870d4f0':
  Remove hardcoded ICU include paths.

ICU exports them using LOCAL_EXPORT_C_INCLUDE_DIRS.

bug: 18581021
Change-Id: Ia57b3b4d231966203274b0e7e7b850beb1bd11c0

* commit '919fbb99':
  Minikin: Remove unused variables, fix init order

* commit 'cb20a2f0':
  Minikin: Remove unused variables, fix init order

* commit '58b25145':
  Move coverage bitmap from FontCollection to FontFamily

* commit '13f1aae0':
  Move coverage bitmap from FontCollection to FontFamily

For build-system CFLAGS clean-up, fix unused variables.

Reorder initializer list to initialize in the order of member
declarations.

Change-Id: I64358b2dcf0e39d0f4e18fdc3473de867f84fcba

This will significantly reduce memory usage and also speed the creation
of new font families. In particular, the coverage bitmaps for the fonts
in the fallback stack will be computed once in the Zygote, rather than
separately in each app process.

Bug: 17756900
Change-Id: I66f5706bddd4658d78fe5b709f7251ca9d2ff4f8

* commit 'dc81fbad':
  Move frameworks/minikin over to libc++.

* commit '69d4fba2':
  Move frameworks/minikin over to libc++.

Bug: 15193147
Change-Id: I5e15c95415c39515340e2663acd5fd26666db720

* commit '253320d2':
  Move coverage bitmap from FontCollection to FontFamily

This will significantly reduce memory usage and also speed the creation
of new font families. In particular, the coverage bitmaps for the fonts
in the fallback stack will be computed once in the Zygote, rather than
separately in each app process.

Bug: 17756900
Change-Id: I66f5706bddd4658d78fe5b709f7251ca9d2ff4f8

* commit '5f11abd3':
  Silently ignore invalid rangeOffset values

Some fonts contain a cmap segment for char 0xffff that contains an
invalid rangeOffset. This was rejected by the existing code, which
means the font is considered to have empty Unicode coverage. This patch
just discards the invalid segment (consistent with OpenType Sanitizer),
making the custom font display.

Bug: 18106256
Change-Id: Icc8616a3030f80e62db906332be64d434ae72ea2

* commit 'd5804e39':
  Fine-tune fake-bolding condition

The old logic for fake bolding results in no fake bolding for a bold
span on a light weight (300) because the target weight (600 in this
case) didn't meet the condition. This patch fine-tunes the threshold
to enable fake bolding for this.

Bug: 17587185

Change-Id: I04abd00a74240cbed79c417f81486aa2158b2806

* commit '6740536e':
  Snap advance widths to integers

Fractional advance widths were causing subtle problems with text
positioning when the same text was drawn with different spans in the
hwui renderer. Quantizing the coordinates on layout (as opposed to
waiting until the renderer draws the glyphs) solves the problem.

This patch also fixes a discrepancy between x position and advance
widths when letterspacing.

Bug: 17347779
Change-Id: Ia705944047408c2839d5ad078eefd6bbec446872

* commit '997c799e':
  Try Unicode decomposition for selecting fallback font

This patch finds an appropriate fallback font in the case where no font
directly maps the requested character, but a font does exist for the
character's canonical decomposition. This yields correct rendering of
compatibility characters such as U+FA70.

Bug: 15816880
Bug: 16856221
Change-Id: Idff8ed6b942fec992a0815a32028b95af091d0ee

* commit '56c7fb8c':
  Allocate font vector on stack

This reduces another allocation (last one?) we were doing when
fulfilling shaping requests from the cache.

Bug: 17111260
Change-Id: Ieb8ae1ccfcaacedb257e1e9263777f10623aaf98

* commit '6da7796c':
  Fix Layout initialization in the skipCache path

C++ local var initialization always tricks me.  Previously, Layout
didn't have a constructor, which meant that defining it on the stack
left mAdvance uninitialized.  This was not an issue when we were doing
"new Layout()", since that invokes zero-initialization, but was an
issue for the skipCache path that was allocating layout on stack by
just "Layout l" instead of "Layout l = Layout()".  To avoid surprises,
add a constructors that clears everything.

Also adds reset() method to reset the layout for reuse.

Change-Id: I3e02f00da9dd7d360abe13f63c310f6882292d0a

* commit '288c9159':
  Speed up cache lookup

Avoid copying the string for cache lookup.

Bug: 17111260
Change-Id: Ic220bfc991fc6b3dada197304aabdf72a8941bd7

* commit 'f952161b':
  Choose same font for Emoji keycap and its base character

The U+20E3 COMBINING KEYCAP is used in our fonts to generate an emoji
rendering of ASCII numbers and letters through GSUB.  For that to work
we need to choose the same (Emoji) font for the character coming
*before* the COMBINING KEYCAP character.

This is a special-case of a broader need to choose fonts per grapheme
cluster as opposed to per character, but for now, special-case U+20E3.

Bug: 7557244
Change-Id: I958e5a01068df8495bbb9bc3b9ed871cea1838b6

* commit '5986f604':
  Support fontFeatureSettings

Bug: 15246510
Change-Id: I544915d29b2be4fb9f82f1989188a3a918c50fbc

* commit '9802b0dc':
  Fix examples build

* commit 'd50c99df':
  Remove CSS string doLayout entrypoint and supporting code

* commit '83d5a3c5':
  Initialize MinikinPaint members

Was broken after recent CSS removal.

Change-Id: I160fbc73286b21336d6f3943ff92d7d150dff74b

We are stack-allocating MinikinPaint objects in Minikin clients, and
without a constructor adding new members to the struct cannot be done
without updating all clients (only one right now!).

Change-Id: I4170f16498bb6b07cb795495011aca58087ed0bd