chromium: Add component-build PACKAGECONFIG option

In a component build, the individual Chromium components are contained in
separate shared objects. This is useful when building on a system with
8 GB RAM or less (since the linker needs at least that much for link
time optimization otherwise if a non-component build is done), and during
development and testing of Chromium internals.

Signed-off-by: Carlos Rafael Giani <dv@pseudoterminal.org>
Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
chromium: Add variable to contain extra command-line arguments

With this patch it becomes possible to add extra command line options to
the "chrome" call in /usr/bin/google-chrome script .

Signed-off-by: Carlos Rafael Giani <dv@pseudoterminal.org>
Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
chromium: Add use-egl PACKAGECONFIG option

By default, Chromium will try to use GLX and regular OpenGL. On embedded
platforms, these are often not present, or unaccelerated, and using EGL
and OpenGL ES instead makes more sense. To produce builds that use EGL and
OpenGL ES by default instead, this PACKAGECONFIG option can be used.

An EGL/OpenGLES-enabled build produces a chromium version that renders
2D and WebGL with GPU acceleration (if present).

Signed-off-by: Carlos Rafael Giani <dv@pseudoterminal.org>
Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
chromium: Add ignore-lost-context PACKAGECONFIG option

Accelerating the HTML5 canvas element rendering with OpenGL ES is tricky,
because an EGL context can get lost with some drivers. Since pages using
canvas assume they can paint into the canvas and the pixels inside will
never vanish, this is a problem. Workarounds like periodic snapshots are
being considered. The WHATWG discussion about this problem can be found at:
http://lists.whatwg.org/htdig.cgi/whatwg-whatwg.org/2012-September/206450.html

Until then, one has to choose: either no acceleration and full standards
compliance, or acceleration and potentially lost pixels.

Using this PACKAGECONFIG chooses the second option.

Signed-off-by: Carlos Rafael Giani <dv@pseudoterminal.org>
Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>