Support RGBA fonts and bitmap fonts (and RGBA bitmap fonts)

Quite a few things going on in this commit:

- Enable bitmap strikes by default in Paint objects.

The SkPaint parameter that enables bitmap strikes was not previously
included in DEFAULT_PAINT_FLAGS. This effectively disabled bitmap
fonts. Oops! It's for the best, though, as additional work was needed
in Skia to make bitmap fonts work anyway.

- Complain if TEXTURE_BORDER_SIZE is not 1.

Our glyph cache code does not currently handle any value other than 1
here, including zero. I've added a little C preprocessor check to
prevent future engineers (including especially future-me) from
thinking that they can change this value without updating the related
code.

- Add GL_RGBA support to hwui's FontRenderer and friends

This also happened to involve some refactoring for convenience and
cleanliness.

Bug: 9577689
Change-Id: I0abd1e5a0d6623106247fb6421787e2c2f2ea19c
diff --git a/libs/hwui/Caches.cpp b/libs/hwui/Caches.cpp
index 6ac637e..df966e1 100644
--- a/libs/hwui/Caches.cpp
+++ b/libs/hwui/Caches.cpp
@@ -256,8 +256,12 @@
     log.appendFormat("  PatchCache           %8d / %8d\n",
             patchCache.getSize(), patchCache.getMaxSize());
     for (uint32_t i = 0; i < fontRenderer->getFontRendererCount(); i++) {
-        const uint32_t size = fontRenderer->getFontRendererSize(i);
-        log.appendFormat("  FontRenderer %d       %8d / %8d\n", i, size, size);
+        const uint32_t sizeA8 = fontRenderer->getFontRendererSize(i, GL_ALPHA);
+        const uint32_t sizeRGBA = fontRenderer->getFontRendererSize(i, GL_RGBA);
+        log.appendFormat("  FontRenderer %d A8    %8d / %8d\n", i, sizeA8, sizeA8);
+        log.appendFormat("  FontRenderer %d RGBA  %8d / %8d\n", i, sizeRGBA, sizeRGBA);
+        log.appendFormat("  FontRenderer %d total %8d / %8d\n", i, sizeA8 + sizeRGBA,
+                sizeA8 + sizeRGBA);
     }
     log.appendFormat("Other:\n");
     log.appendFormat("  FboCache             %8d / %8d\n",
@@ -272,7 +276,8 @@
     total += dropShadowCache.getSize();
     total += patchCache.getSize();
     for (uint32_t i = 0; i < fontRenderer->getFontRendererCount(); i++) {
-        total += fontRenderer->getFontRendererSize(i);
+        total += fontRenderer->getFontRendererSize(i, GL_ALPHA);
+        total += fontRenderer->getFontRendererSize(i, GL_RGBA);
     }
 
     log.appendFormat("Total memory usage:\n");