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/shared/OpenglCodecCommon/SocketStream.cpp

@@ -84,6 +84,11 @@ void *SocketStream::allocBuffer(size_t minSize)
 };
 
 int SocketStream::commitBuffer(size_t size)
+{
+    return writeFully(m_buf, size);
+}
+
+int SocketStream::writeFully(const void* buffer, size_t size)
 {
     if (!valid()) return -1;
 
@@ -91,7 +96,7 @@ int SocketStream::commitBuffer(size_t size)
     int retval = 0;
 
     while (res > 0) {
-        ssize_t stat = ::send(m_sock, (const char *)(m_buf) + (size - res), res, 0);
+        ssize_t stat = ::send(m_sock, (const char *)buffer + (size - res), res, 0);
         if (stat < 0) {
             if (errno != EINTR) {
                 retval =  stat;