Since switching to 64-bit devices, size_t is now a 64-bit integer.
FontCollection::Range uses two size_t integers but they just point to an index
in mFamilies. To reduce the memory usage, this CL changes the size_t integers to
uint8_t.
The maximum size of each integer in Range is the size of FontCollection::mFamilies.
The largest this can go is the system font list plus a user defined family, which
has 91 families. So an 8-bit integer should be enough.
With this change, about 84 KiB of memory will be saved per font collection. Since
eight font collections are created during bootstrap, about 670 KiB of memory will
be saved with this CL.
Bug: 33562608
Test: Ran FontCollection.collectionAllocationSizeTest on a 64-bit device.
On my Nexus 5X, it changed from 327358 to 241342.
Change-Id: I9e01d237c9adcb05e200932401cb1a4780049f86
41ef8b376f