Enable SurfaceTexture based zero-copy texture uploading on Android platform

content/common/gpu/client/gpu_memory_buffer_impl_surface_texture.cc

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "content/common/gpu/client/gpu_memory_buffer_impl_surface_texture.h"
+
+#include "base/logging.h"
+#include <android/native_window_jni.h>
+
+namespace content {
+
+GpuMemoryBufferImplSurfaceTexture::GpuMemoryBufferImplSurfaceTexture(
+    gfx::Size size,
+    unsigned internalformat)
+    : GpuMemoryBufferImpl(size, internalformat),
+      texture_id_(0),
+      native_window_(NULL),
+      stride_(0),
+      stride_updated_(false) {}
+
+GpuMemoryBufferImplSurfaceTexture::~GpuMemoryBufferImplSurfaceTexture() {}
+
+bool GpuMemoryBufferImplSurfaceTexture::Initialize(
+    gfx::GpuMemoryBufferHandle handle) {
+  texture_id_ = handle.texture_id;
+  surface_texture_ =
+      reinterpret_cast<gfx::SurfaceTexture*>(handle.surface_texture_handle);
+  stride_ = GpuMemoryBufferImpl::GetStride();
+  return true;
+}
+
+void GpuMemoryBufferImplSurfaceTexture::setNativeWindow(ANativeWindow* window) {
+  native_window_ = window;
+  if (native_window_) {
+    if (ANativeWindow_setBuffersGeometry(native_window_,
+                                         size_.width(),
+                                         size_.height(),
+                                         WINDOW_FORMAT_RGBA_8888))
+      return;

[Hongbo Min, 2014/03/18 06:10:03]

Error log if ANativeWindow_setBuffersGeometry fails?

+  }
+}
+
+void GpuMemoryBufferImplSurfaceTexture::Map(AccessMode mode, void** vaddr) {
+  DCHECK(!mapped_);
+  *vaddr = NULL;
+  if (!native_window_)

[Hongbo Min, 2014/03/18 06:10:03]

Need to return if it is already mapped.

+    return;
+  ANativeWindow_Buffer buffer;
+  if (ANativeWindow_lock(native_window_, &buffer, 0))

[Hongbo Min, 2014/03/18 06:10:03]

It may need to have a pair calling of ANativeWindow_unlockAndPost if
ANativeWindow_lock returns 0.

+    return;
+
+  *vaddr = reinterpret_cast<void*>(buffer.bits);
+  stride_ = buffer.stride * 4;
+  stride_updated_ = true;
+  mapped_ = true;
+}
+
+uint32 GpuMemoryBufferImplSurfaceTexture::GetStride() const {
+  if (!stride_updated_) {
+    LOG(WARNING) << "stride is not updated, a default stride is returned.";
+    LOG(WARNING) << "stride is: " << stride_ << ", width is " << size_.width();
+  }
+  return stride_;
+}
+
+void GpuMemoryBufferImplSurfaceTexture::Unmap() {
+  DCHECK(mapped_);
+  if (!native_window_)

[Hongbo Min, 2014/03/18 06:10:03]

Does it also need to return if 'mapped' is false? so that Release build won't
run ANativeWindow_unlockAndPost.

+    return;
+  ANativeWindow_unlockAndPost(native_window_);
+  mapped_ = false;
+}
+
+gfx::GpuMemoryBufferHandle GpuMemoryBufferImplSurfaceTexture::GetHandle()
+    const {
+  gfx::GpuMemoryBufferHandle handle;
+  handle.type = gfx::SURFACE_TEXTURE_BUFFER;
+  handle.texture_id = texture_id_;
+  handle.surface_texture_handle = reinterpret_cast<void*>(surface_texture_);
+  return handle;
+}
+
+}  // namespace content