Bug 754872. Avoid using two passes to draw glyphs on mobile. r=joe

Chrome & Safari both use a single pass for overlapping glyphs. We shouldn't try
so hard when running on mobile.

gfx/cairo/cairo/src/cairo-image-surface.c

@@ -4031,7 +4031,13 @@ _cairo_image_surface_glyphs (void			*abstract_surface,
     composite_glyphs_info_t glyph_info;
     cairo_clip_t local_clip;
     cairo_bool_t have_clip = FALSE;
+#ifdef MOZ_GFX_OPTIMIZE_MOBILE
+    // For performance reasons we don't want to use two passes for overlapping glyphs
+    // on mobile
+    cairo_bool_t overlap = FALSE;
+#else
     cairo_bool_t overlap;
+#endif
     cairo_status_t status;
 
     cairo_rectangle_int_t rect;
@@ -4045,7 +4051,12 @@ _cairo_image_surface_glyphs (void			*abstract_surface,
 							  scaled_font,
 							  glyphs, num_glyphs,
 							  clip,
+#ifdef MOZ_GFX_OPTIMIZE_MOBILE
+							  NULL);
+#else
 							  &overlap);
+#endif
+
     if (unlikely (status))
 	return status;
 

layout/reftests/bidi/reftest.list

@@ -1,4 +1,4 @@
-fails-if(Android) == bdi-element.html bdi-element-ref.html # sub-pixel AA
+== bdi-element.html bdi-element-ref.html
 == bidi-000.html bidi-000-ref.html
 == bidi-001.html bidi-001-ref.html
 == bidi-001-j.html bidi-001-ref.html

layout/reftests/counters/reftest.list

@@ -60,4 +60,4 @@
 == text-boundaries-subpixel.html text-boundaries-subpixel-ref.html
 == counter-hebrew-test.html counter-hebrew-reference.html
 == counters-hebrew-test.html counters-hebrew-reference.html
-fails-if(Android) == counter-reset-integer-range.html counter-reset-integer-range-ref.html
+== counter-reset-integer-range.html counter-reset-integer-range-ref.html

layout/reftests/generated-content/reftest.list

@@ -1,4 +1,4 @@
-fails-if(Android) == display-types-01.html display-types-01-ref.html
+== display-types-01.html display-types-01-ref.html
 == dynamic-attr-01.html dynamic-attr-01-ref.html
 == dynamic-restyle-01.html dynamic-restyle-01-ref.html
 == floated-01.html floated-01-ref.html