Enable SurfaceTexture based zero-copy texture uploading on Android platform

content/renderer/render_thread_impl.cc

Index: content/renderer/render_thread_impl.cc
diff --git a/content/renderer/render_thread_impl.cc b/content/renderer/render_thread_impl.cc
index 753244fbd4e2fc9e7c22bdeae970e52645a8215a..e65e01a0e0d8d095547c3b7947da616fc00db89f 100644
--- a/content/renderer/render_thread_impl.cc
+++ b/content/renderer/render_thread_impl.cc
@@ -1102,21 +1102,29 @@ scoped_ptr<gfx::GpuMemoryBuffer> RenderThreadImpl::AllocateGpuMemoryBuffer(
     return scoped_ptr<gfx::GpuMemoryBuffer>();
 
   gfx::GpuMemoryBufferHandle handle;
-  bool success;
-  IPC::Message* message =
-      new ChildProcessHostMsg_SyncAllocateGpuMemoryBuffer(width,
-                                                          height,
-                                                          internalformat,
-                                                          &handle);

[reveman, 2014/02/26 08:02:34]

Please don't change any of code in this function. This is currently not a place
for platform or implementation specific code.

Even if you're not going to allocate the SurfaceTexture on the browser process
side (but that might be better, if possible?) still perform this sync IPC for
now and have it return a gfx::GpuMemoryBufferHandle with type set to
gfx::SURFACE_TEXTURE_BUFFER.

Don't worry about the unnecessary round-trip for now. I'd like to see a first
implementation of this that is as clean as possible. Once we've landed that and
have some good data on how it performs we can investigate Android specific
shortcuts that will improve performance.

The cost of the round-trip here has to be reduced anyhow (crbug.com/346712) so
it's likely not going to be a problem in the long run.

 
-  // Allow calling this from the compositor thread.
-  if (base::MessageLoop::current() == message_loop())
-    success = ChildThread::Send(message);
-  else
-    success = sync_message_filter()->Send(message);
+#if defined(OS_ANDROID)
+  bool is_android = true;
+#else
+  bool is_android = false;
+#endif
 
-  if (!success)
-    return scoped_ptr<gfx::GpuMemoryBuffer>();
+  if (!is_android || !CommandLine::ForCurrentProcess()->HasSwitch(
+                          switches::KEnableSurfaceTextureBuffer)) {
+    bool success;
+    IPC::Message* message = new ChildProcessHostMsg_SyncAllocateGpuMemoryBuffer(
+        width, height, internalformat, &handle);
+
+    // Allow calling this from the compositor thread.
+    if (base::MessageLoop::current() == message_loop())
+      success = ChildThread::Send(message);
+    else
+      success = sync_message_filter()->Send(message);
+
+    if (!success)
+      return scoped_ptr<gfx::GpuMemoryBuffer>();
+  } else
+    handle.type = gfx::SURFACE_TEXTURE_BUFFER;
 
   return GpuMemoryBufferImpl::Create(
       handle,