Use GL_LINEAR for backing texture of offscreen framebuffer.

gpu/command_buffer/service/gles2_cmd_decoder.cc

Index: gpu/command_buffer/service/gles2_cmd_decoder.cc
diff --git a/gpu/command_buffer/service/gles2_cmd_decoder.cc b/gpu/command_buffer/service/gles2_cmd_decoder.cc
index 7e5f94223651dab84daffc5b04579490d55f3356..43511dbc550a26e6bdc426131fe83d55638e1d4d 100644
--- a/gpu/command_buffer/service/gles2_cmd_decoder.cc
+++ b/gpu/command_buffer/service/gles2_cmd_decoder.cc
@@ -2019,8 +2019,8 @@ void BackTexture::Create() {
   Destroy();
   glGenTextures(1, &id_);
   ScopedTextureBinder binder(state_, id_, GL_TEXTURE_2D);
-  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
-  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 
@@ -3293,13 +3293,13 @@ void GLES2DecoderImpl::UpdateParentTextureInfo() {
       GetErrorState(),
       offscreen_saved_color_texture_info_.get(),
       GL_TEXTURE_MAG_FILTER,
-      GL_NEAREST);
+      GL_LINEAR);
   texture_manager()->SetParameteri(
       "UpdateParentTextureInfo",
       GetErrorState(),
       offscreen_saved_color_texture_info_.get(),
       GL_TEXTURE_MIN_FILTER,
-      GL_NEAREST);
+      GL_LINEAR);
   texture_manager()->SetParameteri(
       "UpdateParentTextureInfo",
       GetErrorState(),