emulator: opengl: 'large' buffer optimization

This patch modifies the guest encoding libraries to avoid
un-necessary copies when sending large buffers (e.g. pixels)
to the host. Instead, the data is sent directly through a
new IOStream method (writeFully()).

On my machine, this improves the NenaMark2 benchmark
(from 50.8 to 57.1 fps). More importantly, this speeds up
the display of non-GL surfaces too, which are sent through
the special rcUpdateColorBuffer() function in gralloc_goldfish.

This is noticeable in many parts of the UI (e.g. when scrolling
through lists).

To tag a given parameter, use the new 'isLarge' variable flag
in the protocol .attrib file.

Implemented for the following encoding functions:

  rcUpdateColorBuffer
  glTexSubImage2D
  glTexImage2Di
  glBufferData
  glBufferSubData
  glCompressedTexImage2D
  glCompressedTexSubImage2D
  glTexImage3DOES
  glTexSubImage3DOES
  glCompressedTexImage3DOES
  glCompressedTexSubImage3DOES

+ Optimize the auto-generated encoder functions to avoid
  repeated function calls (for size computations).

Change-Id: I13a02607b606c40cd05984cd2051b1f3424bc2d0

tools/emulator/opengl/host/include/libOpenglRender/IOStream.h

@@ -34,6 +34,7 @@ public:
     virtual int commitBuffer(size_t size) = 0;
     virtual const unsigned char *readFully( void *buf, size_t len) = 0;
     virtual const unsigned char *read( void *buf, size_t *inout_len) = 0;
+    virtual int writeFully(const void* buf, size_t len) = 0;
 
     virtual ~IOStream() {
 
@@ -82,6 +83,7 @@ public:
         return readFully(buf, len);
     }
 
+
 private:
     unsigned char *m_buf;
     size_t m_bufsize;