Remove Android specifc LUMP_OF_MEMORY.

Adjust Android heap sizes.

This improves performance on heavy pages by increasing
max_executable_size_ and max_old_generation_size_.

There is now no need for an Android specific LUMP_OF_MEMORY.

Committed: https://code.google.com/p/v8/source/detail?r=11740

[ulan, 2012-06-08 08:54:13]

This would make max_old_generation_size_==700MB. On my devices Dalvik VM heap
size is 256MB.

What if we special case initialization of old and code space sizes for Android
to some value < 256MB?

     max_old_generation_size_(192 * MB),
     max_executable_size_(192 * MB),

[ulan, 2012-06-08 10:32:16]

LGTM. Thank you, I will land it for you.