gpu: Add GpuFence framework.

gpu/command_buffer/client/gles2_implementation.cc

Index: gpu/command_buffer/client/gles2_implementation.cc
diff --git a/gpu/command_buffer/client/gles2_implementation.cc b/gpu/command_buffer/client/gles2_implementation.cc
index 3424bc2a5310224463bbed535e1e84eed8e336d0..5884f51c3a88900d8acf3545cb30ae438b605881 100644
--- a/gpu/command_buffer/client/gles2_implementation.cc
+++ b/gpu/command_buffer/client/gles2_implementation.cc
@@ -6285,6 +6285,38 @@ GLuint GLES2Implementation::CreateGpuMemoryBufferImageCHROMIUM(
   return image_id;
 }
 
+GLuint GLES2Implementation::CreateFenceCHROMIUMHelper(ClientFence fence) {
+  int32_t fence_id = gpu_control_->CreateFence(fence);
+  if (fence_id < 0) {
+    SetGLError(GL_OUT_OF_MEMORY, "glCreateFenceCHROMIUM", "fence_id < 0");
+    return 0;
+  }
+  return fence_id;
+}
+
+GLuint GLES2Implementation::CreateFenceCHROMIUM(ClientFence fence) {
+  GPU_CLIENT_SINGLE_THREAD_CHECK();
+  GPU_CLIENT_LOG("[" << GetLogPrefix() << "] glCreateFenceCHROMIUM()");
+  GLuint fence_id = CreateFenceCHROMIUMHelper(fence);
+  CheckGLError();
+  return fence_id;
+}
+
+void GLES2Implementation::DestroyFenceCHROMIUMHelper(GLuint fence_id) {
+  // Flush the command stream to make sure all pending commands
+  // that may refer to the fence_id are executed on the service side.
+  helper_->CommandBufferHelper::Flush();
+  gpu_control_->DestroyFence(fence_id);
+}
+
+void GLES2Implementation::DestroyFenceCHROMIUM(GLuint fence_id) {
+  GPU_CLIENT_SINGLE_THREAD_CHECK();
+  GPU_CLIENT_LOG("[" << GetLogPrefix() << "] glDestroyFenceCHROMIUM("
+                     << fence_id << ")");
+  DestroyFenceCHROMIUMHelper(fence_id);
+  CheckGLError();
+}
+
 bool GLES2Implementation::ValidateSize(const char* func, GLsizeiptr size) {
   if (size < 0) {
     SetGLError(GL_INVALID_VALUE, func, "size < 0");